I have replaced the Transmission in my 2000 Jeep Grand Cherokee and just fixed the belnd doors for the heat. Also, I have put 700 dolalrs worth of tires on my jeep 3 months ago. I have put over 3k in my jeep and now the engine just died. I don't know if I can find a cheap motor that is refurbished or reconditioned for 1500 or less or if I should just try and sell the jeep without a motor and get a different car. Problem is I've only got 2k to work with and I love my jeep :(

I can't make financial decisions for you but if you want to do the work yourself, you can usually get a scrapyard engine for under $1,000. If you can hear it run before you buy it that's a plus. I generally take engines from vehicles that have been hit in the rear etc, never from one that looks clean...reason is that a clean body tells me there probably were other mechanical problems that prompted the owner to scrap it. The "accident victim" may have been running perfectly and would still have been on the road if it hadn't been hit. If you are using a good local shop, you may use up the entire 2K after you factor in labor, fluids etc into the job cost
As a rule, you never recover what you put into a vehicle when selling it unless you got it free, especially since most of what you have done is "normal" repair work except for the expensive tires.
Good luck!!