Hey, welcome.
You could try a muffler delete, it's an extremely common mod for all cars. Just search on YouTube for "Celica GTS muffler delete" or something similar and you can decide if it fits your taste. Around here, that would probably like $50 so not too much. If you really want to save money, you could just unbolt the muffler from the tailpipe, as many others have also done.
-Connor