NTK’s club fee is $395 and includes practice days.
Depending on how many runs you do at practice and race days, I think you would have more hours on the motor. I typically estimate an hour of engine time per race day, and 2 hours (minimum) for practice days.
Also, I know you’re just looking for seat time and practice on practice days, and I know you plan on running different fuel to save money, but I would run the same gas in practice that I would be using to race with. Tuning could be different between the 2 fuels, plus it’s just more consistent using the same fuel.
Also, if you got membership at NTK, they have a place where people throw their old tires that if you’re adventurous enough, you can get several sets of used tires for free.