found some rubicon express front coil springs on craigslist 7.5" for 150 dollars I was wondering the actual lift it would do and what else my ole' xj would need for them to go on

Would lift about 7.5" you would need a new track bar, steering, sye, full leaf packs, brake lines... and much more.
There's no reason for a 7.5" lift its just too high...
Oh and you can buy the springs new for that price pretty much lol