depends on how you define cheap. You can pick up a K&N filter on ebay for $20 or so, pick up a Densecharger MAF to TB pipe for $60 or so and that should be ok for your intake for now. Also on the less expensive side, you can buy 2 flowmaster 2 chamber mufflers on Ebay for $106 shipped, take it to a decent local exhaust shop and have them welded on for $60-$100 (call around for best price, mine was $65 at Meineke). An Off-road pipe is ~$150 and can be installed yourself. UD pullies are $150 but you need to rent a few tools for the install. Timing adjuster is probably another $150, installs easily.
Thats really about it, anything more than that requires >$200.