Something like the P-40 is a good option from Flite Test if you're not looking to upgrade to a new transmitter and battery. If you have a dollar store near you that sell foam board, you can build most FT designs for a few bucks plus whatever you spend on the electronics.
Something like Viggen will fly on a 3s 64mm EDF, but most EDFs these days use 4s. All told, you can build a Viggen for under $100, but you'll still need a transmitter for it. If you plan on flying anything particularly advanced, you will either need to buy a more advanced transmitter of get very good at tiny stick movements. Most planes, FT planes included, benefit from having control over the rates.