there is no way you can expect to do OEM or better paint work only spending $50 on a gun.
You will spend at least $150 for an "okay" gun. Get a Devilbiss Gravity Feed gun. most paint/tool companies carry them.
shoot, even ebay has em.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=22779&item=4303892253&rd=1
*edit: you will need to get a smaller tip for that gun. that is setup with a larger bored primer tip. but it gives you an idea.
