It really depends on your purchases too, if you don't do your research and you're not hungry for a bargain your budget can quickly dwindle after just a few transactions.

Avoid the expensive eBay items but keep an eye out for misspelt and poorly advertised goodies. Some people spell Weber as Webber. You'd be surprised how many auctions are poorly advertised and thus sold for cheap.

For carburettors Mikuni and dellorto are much cheaper and arguably superior in several aspects.