Wow. . . maybe if you want to go that cheap you should get into model cars. . .

IMO, you need a full body kit if you do one at all. . .

There is no cheap HP upgrade. . .ever. You could do poormans CAI with a K&N filter and a dropped resonator, but its not going to give you a huge boost. . .particularly if you dont have an manual tranny and dont often get into the RPM range where a CAI matters most. . .

Also, in the future, be sure to give some technical information on your car, type, year, previous mods etc. . . I;m assuming accord because you've posted here but that really isnt enough. . .