Walgreens does it around here for about $.20 per picture. I have a good Canon printer, and I only buy Canon photo paper when it is on sale and I only buy cheap generic inks off the internet, and I come close to that $.20 per picture price. I find it a little more convenient to do it at home than send them to Walgreens, but there really isn't that big of a difference.
I just saw your note about 300-500 pics per year. I print at least that many for my wife's scrapbooking addiction, and this is the cheapest way that I've found to do it. I'll print at least 50 pictures per month.