now if you want affordable to start.. get a balsa usa enforcer and convert it. you can get into a jet completely for less than the price of a kit.This is commonly called a Byro -blaster........and some have even put turbines on them.
If you want a semi-scale jet and can't find the byron f16(watch Ebay) then go with Top Gun f15. And try to find some help so you first jet goes together right and doesn't weigh alot.
Good Luck