There are lots of ways to save money on tires but it involves work. Generally I will run a new set of tires for quali's and main, then depending on how they look I may get another full day on them and sometimes even 2. If they have any meat left I use them for practice after that until they are useless and then I may keep em a bit longer and use in the street for engine break in. If you buy tires with good foam you can cut the foams out and then use acetone to desolve the glue and then re-use the rims as well. Like I said though, it's allot of work to save $20