To do the wireless network, you would need a wireless router, a wireless connection to your computer and a wireless printer server. Looking at Newegg, a Netgear wireless G router is about $40, a wireless ad apter for your computer would run $30-$40, and the print server would run from $75 to $150, for a total between $150 - $250. You might (should) be able to skip the router and go straight from the computer to the print server, saving $40.
A USB to Cat5 extender will run you $50 to $75, depending on whether you want powered or not. For the printer, you may well want a powered model. They are pretty simple. USB to the computer end of one extender, Cat 5 (ethernet cable) from extender to extender, USB from the remote extender to the printer. Supposed to be good out to about 200 feet.