Hi L..
We've had great luck with the Sears Portrait Studio at the Rice Street Sears. It's cheap ($25 for two years of unlimited sittings) and you're not obligated to buy any prints. The quality has been great, and they're now all-digital so they can adjust the zoom/cropping on pictures. We tend to go three times a year. My son has sometimes been very shy, and they've always been patient with him, which I love.
Prints tend to be $7.99 per sheet, although they have sales. Or, if there's one pose you like, you can get a portrait package for $9.99 (35 pictures) and then buy a proof sheet for $14 if there are other poses you want to remember but don't need 14 wallet prints of.