I have tried Sam's, Costco, and Walgreens and had inconsistent quality. I am trying hard on becoming a better photographer and find I like larger prints on soft matte finish papers.
For several years I used an Epson printer but it jammed too easily and swallowed ink like it was water. I now have a Canon pro 9500. I LOVE this printer. It is expensive but it has not jammed once in three years; resulting in no wasted ink or paper. The colors are true and accurate. I highly sing its praises if you choose to do your own printing!
Occasionally I have used Costco when I have hundreds of images from a trip..then I'll reprint the special ones on matte paper to use on cards, scrapbooks or frame.