You can usually score F4.6's(or F .28's search for either) on ebay for around $120-140 new that were pulled out of savage X's
manifold, and pipe shouldn't be that much probably around $50-60 for both (depends how good of a tuned pip you want there are some for $25)
Servo minimum I would say would be a Hitec 645MG I will be honest its been a while since I bought servos, and don't know if there are better ones then that for less. throttle servo any fast servo should do IMO
Radio Flysky GT2 for $20 would do ya fine I own a few Flysky radios, and they never gave me any real issues. Now I will admit these radios don't have the bells, and whistles the more expensive radios have(which only highly competitive racers really use), but for just having fun they are perfectly suitable.

Dunno someone might know a better setup for less so don't go 100% off what I said wait on ordering for other opinions as I've not really ordered any thing for 1/8th scale RC's in awhile.