I've been through this process over the past few years as I've exhibited and sold a few prints. As others point out, the cost of a decent printer and inks isn't worth it if your print run is small and infrequent. I have an old Epson 220 for the odd A4 and smaller colour print for home use, although at c 5p a print the online mainstream labs are excellent and I put in a few arty shots for proofs to the family print order. I've found Snapfish to be really good, I preferred the look of the prints to Photobox. Advance bulk purchase of a specific size, eg 500 6x4's really brings the price down and you can then use up your stock as time permits.
B+W magazine issue 112 (June 2010) ran no winners/no losers comparison article on various print companies which also contained some good advice. Here are my edited highlights
- if the print will be framed then semi-gloss to matt finishes are better at reducing flare
- the quality of the C-type prints were universally great (less so from SnappySnaps) and cheaper, if the print will be permanently framed (you lose some of the physical nature of giclee papers behind glass)
- c-type has a more limited paper range (usually fuji gloss, semi gloss, matt or metallic) and the paper is thinner
- giclee (inkjet) prints have wider ranges of different physical qualities in the papers - baryta, rag, etc etc - and have thicker paper which feels better as a finsihed print