In my previous post, I mentioned that you don't need a wireless print server for wireless printing. I tested this wired print server TP-Link TL-PS110U ($78) for USB printer. Even wireless users can print to the same printer when the wired print server is connected to a wireless router.
TP-Link also has other models - TL-PS110P for parallel printer, TL-PS210U for USB multi-function printer (print, scan, fax, copy) and TL-PS310U for USB multi-function printer with storage server. If you still need a wireless print server, TP-Link also has TL-WPS510U.