Theres really only a very slim chance you wont need a SYE. I would definately budget for one. Anymore I just consider it part of the lift kit.
You cant even count the number of new people that post on here thinking they are going to throw a 4"+ lift on a for couple hundred and then all you read about from them are problems, how this or that didnt work out.
Dont get me wrong, Im all for saving money. At the moment, Im piecing a lift together for my XJ. Im saving money by buying used and building my own, but Im also choosing my pieces very carefully based on loads of research and being in the off road Jeep community for almost 8 years.
When people on here say "SEARCH" its not intended to be rude, its intent is to open up a whole world of experience that just cant be covered in one thread. Try a few different searches, just about everything has been covered at one time or another, you just need to find it.
Welcome aboard and happy spending, (errr, i mean learning).