so ive read that dex and strencth scale really bad and do no damage and its better to just get lightning weapons and up magic with little strength and least possible dex. my question is if I up dex and strength only (no magic)say 50 strength 35-40 dext would you outdamage a lightning weapon with an upgraded physical damage only weapon or does it still not compare?

It won't matter because at 50 strength you can one hand most of the game's strongest weapons which is going to put you at a major advantage in terms of sheer damage output.
 
If you want to make a powerful weapon before then that take advantage of your stats though you should be ascending weapons to Normal.
 
Don't build Dex though, you should focus on End/Vitality over Dex if you want to build a strong melee character. Dex only scales well on lighter weapons and bows where as Vitality will give you more health and Endurance will allow you to wear heavy armor and wield bigger weapons without encumbrance.
 
Getting 50 strength and 40 Dex is going to leave you ate a really high soul level with very little Vitality and Endurance which is going to make you incredibly weak unless you go to a much higher Soul Level. You should always focus on Vitality and Endurance first and then start stacking damage.

Thing is, you will get better damage output by putting a lot those points into endurance because you will be able to execute longer combos and be more mobile.

@VanillaPlant said:

Thing is, you will get better damage output by putting a lot those points into endurance because you will be able to execute longer combos and be more mobile.

This, partially. The amount of strength it takes to match the damage potential of a lightning based build is fairly ridiculous. Until it gets changed, your soul level has to be very very high in order to have a str scaling build with well distributed stats in endurance and vitality that also matches a lightning build in damage.

Question is, do you care about PvP? If you just want to play PvM then don't worry about it. Both str and dex builds are able to survive the game if the player can manage well enough. Whatever you do, do not add a lot to both str and dex. That's all you need to keep in mind really. If you're going with scaling weapons then you pick one stat or the other. Not both.

Yeah scaling sucks right now, but some of the weapons that require a higher strength stat are actually really good, and a ton more fun to use than boring old lightning weapon+5.