I bought
http://cgi.ebay.com/ebaymotors/Jeep...41121407QQihZ003QQitemZ130041121407QQtcZphoto
that kit off ebay several months ago. Kept the factory isolators up front, kit went together in a weekend, settled out to 3.5"
I don't think you can beat 3" of lift spacers and leaves w/ centering pins for under $100 for new parts.
If you want to do it as cheap as is possible, stay at 2"
I was aiming for 3 and crossed the line a bit, my LCAs are too short, I made drop brackets for and bent the brake hardlines, I ended up giving a 3/4' t-case drop a shot and it helped a lot with the driveshaft vibes I'd been getting.
The point is that I intended to do a BB to give me some more clearance in the snow and in rock gardens on the forest service roads, I ended up getting into problems that will take about as much effort to resolve at 3.5" as they would have at 5"
But, unlike a lot of the people here who will tell you to hold off and do it right, I say go for it and just know that you'll have certain compromises in performance as you piece things together - that is just the nature of modifying your DD. I didn't have the funds to go to 5 or 6" when I started, and both the spacers and AALs that I have now will be combined with the next steps I take (new coils and spring packs) to give me a good overall lift.
Go with a 2" spacer and AAL kit, if you're older body style you can fit 31's with no lift if you trim the fenders, so if you lift it 2", trim and go to bigger tires I wouldn't imagine you'll get any rub.
Get new shocks eventually, but if you need to you can get 2" of extensions for the front and use your old rear swaybar links to make BPE's in the rear and get a little bit more length out of those. You can get by for a while on that, but you won't get all the flex out of your suspension.
That will get you rolling and the install will get you familiar with the cast of characters who are going to be giving you a hassle when you take it to the next level (driveline angles, control arm angles, steering alignment). Now look for some used lift coils and figure out something to add to those old packs with the one AAL. Quadratec has the xj upcountry spring packs for something like $60 a side, you could throw your old AAL and an s-10 spring into those packs and end up around 5" for super cheap...