You also need SFI everything
gloves
shoes
balaclava
HANS or necksgen
SA helmet not a motorcycle helmet
full cage thats inspected
That stuff isn't cheap either. Granted I've looked into it for rally, the cage and everything is a little more protective for that. Still, expect to spend maybe $4000 on all of the above? HANS device are expensive, also a good helmet isn't cheap. I know I bought a cheap Pyrotect helmet for autocross, because there is very little risk of crashing there. If I were on a real track I would save up for a good helmet, my life is worth more than $60. Keep that in mind.
If you're on a tight budget, maybe think about doing autocross or some other SCCA racing until you can save money to road race properly. That said I don't know what your financial situation is like, I know you just said on a budget. Best of luck to you, I'd like to get out for some track days as well. Student loans have to be zeroed out first though.
BTW, if you want to do some real W2W racing without a racing license, in NY we have some real cool rallyx style races on frozen lakes. Fantastic racing, no cage needed for car without studded tires. All you need is a helmet, fire extinguisher, and a set of snow tires. It's all ~30mph driving, but on a frozen lake that's very fast hahah. I haven't raced in any yet, but they look incredibly fun. I'll toss a video up just for the hell of it.
https://www.youtube.com/watch?v=p2tFEgUqG0U