i just got my jeep lifted 2.5 inches w/ 35 tires. how much more will it cost to add 1.5 more inches?

 

I've tried, but at 58 it's totally impossible
Try some spacers, stack (2 ) 3/4"ers.......

 

I would suggest going to a 4x4 shop and getting an estimate, or spend some time using the search on this site.
There are many kits out there that will give you the lift you want and depending on how your current kit is setup (springs vs. spacers) you might be able to keep it and go up from there.
If you want to start all over again get something lift the super lift 4 inch lift kit.

This is really such a vague question it is hard to answer.

 

if you don't mind me asking, why are you wanting more lift? I'm just curious because I'm planning on going with the same setup i.e. 2.5 w/ 35s. Thanks in advance.

 

1" body lift is about $100