This thread shows up close how a $50 Epson "Small In One" NX330 prints on letter size glossy...http://photo.net/beginner-photography-questions-forum/00acnx
(scroll down the page to see the print quality sample)
...it can also print on 4x6 as well, maybe not as fast as the PictureMate which I've never used but the PictureMate does start out at $150+, plus the cost of the ink.
There must be far less costly alternatives from Epson that only prints 4x6 size.
If my Epson breaks or becomes clogged, it's so cheap that I just buy another Epson printer. All four inks combined cost more than the printer which also performs flawlessly as a scanner & copier.