I'm willing to try anything on the cheap but how bad/frustrating are the flaws of this game?

I bought it for €15 and it was definitely worth it. However you can screw yourself over by not investing in hacking skills and get stuck (like I did on my second play through) because it's impossible to hack a thing you need to hack in time unless you have some skill points in it to make it faster. Besides that it's been a pleasant experience playing the game despite a few flaws. i really liked it.

Wait.  Have there not been any patches to change the gameplay since release?

I just picked it up for $20 and I can heartily recommend it.

Just finished it as solider and now on a second playthrough with focus on stealth and can also absolutely recommend it (PC version with Xbox360 controller, haven't played on consoles). It has a few issues (feel through the ground twice) and the boss design is kind of old school, but really just very minor stuff. All the complaints on the gun play feel rather unfounded, as the mechanics are really rather easy to understand (the longer you hold your aim, the more precise your shoot gets, nothing new, had that in plenty of other games).
 
I don't really get how Mass Effect can get so much praise and this game so much hate, given that the overall design is extremely similar (even including romancing one of the NPCs) and only really the setting is different. Thats not to say that it is as good as Mass Effect, but it certainly isn't all that far away.
 
My biggest complaint would be:

• lack of Mass Effect like power-wheel, as activating multiple powers requires a few more clicks then it should
  
• no overworld, getting to missions and talk events works via a menu, would have preferred to walk up to characters myself like in ME
• no difficulty switching in the mid of the game (felt it was to easy as solider on normal, but wouldn't recommend a play on "hard" from what I heard)
• stealth feels a little to primitive compared to Splinter Cell games
• generic story, seen that stuff to often in other spy related stuff (i.e. 24), but it makes up for it with interesting characters
  

I am so happy i picked alpha protocol up on the cheep. I really like this game, love how they did the characters.

Took a chance on this game myself a few days ago, and I am totally loving it! 
It has some frustrating mechanics and chechpointing though, but I love the setting and the way dialogue works.

First off,the games combat mechanics are awful,but to be honest,only the shooting was bad, the stealth part wasn't that bad though there are a lot better stealth games.
Also a big problem is the way you access gadgets (grenades,emp charges,medkits) and skills, its pretty bad.
But its the only RPG spy game i have heard of and played,the story is pretty good,it has some interesting characters and the amount of choice and the way they effect the games events is amazing,that alone should be enough for you to buy it.
So yeah,for 15-20 bucks its definitely worth it imo.
Also,a big problem is that almost every mission you go on requires either stealth,or combat, there are some missions where you go just to talk to some characters, but all you can do in those missions is choose dialogue options instead of running around and exploring and then talking to the character/s.

I think the game's definitely worth twenty bucks. Just make sure you do all other missions before tackling Moscow. And upgrade your pistol. That boss tends to be a bitch otherwise.

I just got the game myself and I'm really enjoying it.  
 
But, I really enjoy games that can be played in a fairly deliberate manner (as opposed to more "twitch" ones).  
 
So far (I'm only about 2 hours in), the story is fairly compelling and the game play has been good. 

If you can, I highly recommend the PC version (with a 360 controller as well). It seemed a lot more optimized for that than the console versions. Either way it's an awesome game that unfortunately got overlooked by a lot of people. My only gripe was that it was far too short for me, especially with how interesting the story was. Visually I thought it was pretty damn good looking too.

It has a lot of flaws, but I think it does a better job of weaving dialogue and gameplay than any other game, full stop. If you have any interest in game narratives, you should play it.

" I think the game's definitely worth twenty bucks. Just make sure you do all other missions before tackling Moscow. And upgrade your pistol. That boss tends to be a bitch otherwise. "

"Also,a big problem is that almost every mission you go on requires either stealth,or combat, there are some missions where you go just to talk to some characters, but all you can do in those missions is choose dialogue options instead of running around and exploring and then talking to the character/s. "

YES. Though I played it on PC. Can't speak for any other platforms. One of my favorite games of last year.

Alpha protocol is a great game - for twenty dollars or less. It is just as good as Deadly Premonition.

I know I am in the minority but I loved this game, even at full price.

I just got it too. I love it. I like the spy/assassin type character and the story seems ok (haven't completed  the game yet though). Never played Splinter Cell or the other games this has been compared to, but I've had no big problems playing on PC using a mouse and keyboard (I did have to dial down the mouse sensitivity from the default quite a bit).  
My main problem would be the points of no return on some missions. There are times when you are unsure where to go, make a choice, only to have a door shut behind you and an objective lost to completion.  That and using multiple skills in a row is a bit clunky.