>>1607072pro tip: if you're buying jet-a from a large airport when you have other options available you're a retard
Jet maintenance will put you in the poorhouse though no matter what engine. Also good luck finding a nearby A&P who will touch your obscure cold war era jet trainer at any reasonable cost. There's a reason most guys who fly warbird jets just so happen to be milli/billionaires.
the subsonex might be a good option though if you just want to go fast