Well I'm about to travel through Omega4 relay and all the star clusters on the entire galactic map are 100% explored and all my side missions are done.
I'm pretty sure I've done all the side missions there are since I usually talk to everyone and double check after.
Yet there are still some upgrades in shops left to buy. I have about 90k left and I think about 200-300k worth of stuff to buy.
I only bought stuff for discount prices where possible btw, so didn't waste any money there.
 
So my question is: Is it even possible to fully buy everything in shops for your upgrades in a single playthrough? How?
 
PS: Assuming you don't abuse quicksaving and quickloading betting on damn fights on Tuchanka.
 

You can't buy everything in a single playthrough. You can get closer with the double-money terminal hack glitch.

If you have ever failed hacking a terminal, you might have missed some upgrades. I know I lost a couple this way. As for money. I don't know, but I was never hurting for money.

I was wondering about this too.  On my first playthrough, there were still 3 or 4 upgrades I couldn't afford even after completing all the side quests.  I was pretty anal retentive about exploring, so maybe I spent too much on fuel and probes.  Does the number of upgrades you already have affect the price in stores the same way the mineral cost of research upgrades increases?  In other words, is it cheaper to hold off on researching until you've bought all the upgrades you can first?

Unless you spend hours betting on the pit-fighting, I don't think it's possible. I'm on my second playthrough, using a level 56 ME1 character with the wealthy achievement, and even with all the bonus cash I got to begin with, I'm still short two upgrades (both available near the mechanic on the Krogan homeworld), plus a few others seem to be at 3/5 when I know I've not missed any, unless they've been tucked away in a corner out of the way, and I've done every single side-quest possible (all systems at 100%).

you can get every upgrade through the terminals and about 80% of the ones you have to buy but you cannot get every upgrade with mission aquired money. 
 
requires abuse of the pit fighting which will take forever.

" I hit a fucking wall with Urz when trying to game the fights, so I ended up giving up, but by the time that had happened, after Legion's recruitment and loyalty mission (coincidently, after the Suicide Mission), I managed to buy the last upgrade (tech).  But yeah, gaming the fights is necessary, if only for a short while. After buying the tech upgrade, I think I had a good 30000 left. "

You can't get everything that easy. You have to buy all the armor upgrades in the shop on your first playthrough (you that you already have them), and on the 2nd one make sure to buy only on discounts, and get everything as far as cash goes.
I finished my 2nd playthrough, missed 2-3 armor upgrades before, and I'm missing about 40k to get the last upgrade. There's no way to have enough money without doing the Pit Fights for 500, but you can be close.
 
Hopefully some new DLC adds more money. Also, there are upgrades to have 5/5 on everything. (6/6 for one thing with Zaeed). What's more, there are 6 Heavy Weapon Ammo in the main game, without the Zaeed DLC, but the 6th one doesn't give you anything.

I managed to buy every wep/ship upgrade apart from the scar healing station which wasn't essential for the final mission, the money i saved on not buying probes for the high level req for it might have left me enough money for everything else?

Importing a Rich ME1 character and the Long Service Medal helps a lot with trying to get everything. I think you start out with enough Element Zero that you can buy every possible upgrade in the game.

 Yeah, second playthru (Long Service) with a Rich, level 50/60, me1 import, gives you something like 330k, and more Eezo than you need.  Very nice.  And, double terminal glitch is easy to do.  I can't be 100% without checking, but I'm pretty sure I bought every upgrade in the game on my 2nd and 3rd playthrus without having to do any varren betting. Skip the hacking and bypass upgrades since they're entirely unnecessary.  Of course, make sure you get the discounts at every store before buying too.  Surgeon General Warning: Mining for enough Platinum for all upgrades may cause suicidal thoughts or tendencies.

My biggest hope for DLC is a terminal at Illium where you can trade resources for cash. :)
 
And why the hell won't Cerberus pony up some cash? They just spent millions bringing me back to life. Couldn't they throw in a few hundred thousand more for my upgrades? It's like pocket change to them.

I dunno about anyone else, but on my Vigilante salary I managed to buy every upgrade in one playthrough.
 
Having the Rich achievement requirements surpassed or maybe just having the achievement in general gives a good money grant I think.
 
I got every upgrade and everything I could buy from stores. Without glitching. I just hacked allot of terminals.

" You can't buy everything in a single playthrough. You can get closer with the double-money terminal hack glitch. "

I assume I just missed something but I couldn't find the final assault rifle upgrade for the life of me.

I'm only a few hundred creds away from being able to afford what I think is the last, so it may be possible provided you don't buy any fish... Can only do them after getting Legion though, so it's best to get them after the game, unless you don't mind sacrificing the crew.

" I dunno about anyone else, but on my Vigilante salary I managed to buy every upgrade in one playthrough. "

To buy every upgrade you need to start with having beaten the game one time with an import or twice with an me2 made character to get the long service achievement then import a me1 character with  the rich achievement.   This should net you 350k at the start along with a substantial amount of minerals.  You also need to make sure to play through all side quests and every mission before heading to the IFF.  This will allow you to get enough money to buy all items by the time you head off to the endgame.
 
Additionally, you should also try not to buy too many probes/fuel, buying only enough for the upgrades that you have.  IWith this strategy, I was able to buy every possible upgrade.  Note: that the Zaeed Massani loyalty quest means you give up at least one possible upgrade, as you have to choose your path, although I think it's actually a bonus upgrade.

" @Garrus said:

" I dunno about anyone else, but on my Vigilante salary I managed to buy every upgrade in one playthrough. "

Oh god, the Garrus roleplay is starting to bother me :-/ "

Yeah  ...
So like i finished ME2 twice already almost a month ago :)
Writing in since people seem to still be interested in the topic, I also pretty much confirmed (like others have said) myself that you cannot buy everything on the first play through, only if you start with Rich and Long Service stuff.
I even posted a way to make infinite money without need to reload on pitfights some time ago, but forum ate it couse post glitched and it got posted into General.
 
Also the second time around I couldn't be fucked to do any harvesting (couse it's a shitty time waster minigame imo) so I just gave myself about a million resources each for giggles.