Is this possible? Does anyone have any idea how much it would cost? I am becoming somewhat frustrated with the terrible road conditions in Minneapolis (at least in my neighborhood anyway) and was thinking about converting from 27' wheels to either 700c or 650b with fatter tires. Any info would be greatly appreciated.

seems to me that if you convert to 700c, you should be able to use the same posts. Of course, this depends on how adjustable your brakes are. I believe that many modern cantis are adjustable enough to make the switch. It's only 4mm.

Installing new canti posts will cost you $80-100, and painting a frame ranges from $100 for powder to $400 on up for wet paint

Nah I already checked. It's an older Schwinn passage touring bike and the posts are set too narrow to allow for the 4mm I'd need for 700c (with modern tektro 720 brakes anyway). $80 is a bit too expensive for me. Seeing that the entire bike cost me $375, if I had decided to do this I certainly would have repainted it myself.

Given the cost I guess it was a pretty drastic idea for a solution. Local shop generally sells vintage 531 framesets for $100.

Just annoyed to have broken a spoke whilst unloaded on a 40 spoke touring wheel (I weigh maybe 170lbs).