i am in a similar situation with the zed. i started off with deca's then did a driver dynamics sandown track day and a winton fun day. also did a driver dynamics drift day just for the hell of it. i think my next event will be sandown sprints in June or winton in july with WRX club. car has had no major issues in 3 years, being a NA means you can drive it hard and you won't generate anywhere near as much heat as a turbo car + I can drive all the way to deca, do deca and drive back with and still have 1/3 tank of fuel left haha. it's ok on petrol for daily driving too.
need to keep it well maintained though. regular oil changes and pull the wheels of or lift it up and get under it and give it a thorough checkover regularly to catch any potential issues early. I think i have probably spent a fair bit to make the car "trackworthy" and reliable enough that i can depend on it as a daily driver, but probably nowhere near the cost of having a second car + trailer. maybe when i get out of uni and get a proper job i will consider that option.
i would recommend you keep a bit of money in an account that is your emergency repair fund incase something does break. i have been doing that since i got the car back in 06, haven't needed to use it yet but good to have it just incase so you can get any issues fixed ASAP. chuck it in a high interest internet banking account and then if you end up not using the money then at least you can use it on your next car or house deposit etc.