+ 20 hp and $1000 can it be done without nitrous ?

i have been doing some reading and decided that im not going to get a supercharger , mainly due to financial reasons .and i dont want to go with nitrous because of reliability issues . i think i will go with the bolt on approach . i know the power gains will be minimal compared to a supercharger ot nitrous , but im not looking for extreme gains anyways . i just want my car to be a little more fun to drive . i would like to stay around the $1000 range for parts also . i was thinking of getting a cold air intake , headers , and a cat back exaust system . anyone think i can get around 20 hp out of all these bolt on parts ?