How much money do I have to prepare for an average car modification?

My car is Honda Fit S 2007 MT. I would like to add a subwoofer to my car (the car already completed with AM/FM/CD audio system with 4 speakers), change the rims into a 16” rims with a 195/40 – R16 tires, and change the exhaust resonator to have a little racing sound. With an average quality of parts that mention above, anybody know how much money do I need?How much money do I have to prepare for an average car modification?A good sub with amp and box with wiring like 350, good rims with tires 750, a slip on pipe 125 wit labor.