Im not sure exactally how cheap your talking about but you certainly could put together a DIY turbo kit fairly inexpensively. Whatever route you choose take racnriks advice and check out local swap meets and online classifieds for good deals on parts. Patience is the key when browsing through all the stuff out there not too long ago a buddy came across a used A4 block the owner thought was damaged, turns out it only needed to be honed. My friend offered him $150.00 and he took it.