It would depend on what I'm using the logo for. If I'm using it for a site that I might flip later, or I just need the logo so that the website/blog can "look" professional, then I wouldn't buy a logo for more than $50.
However, if I'm buying the logo for my personal website/branding or for a site that I plan on keeping for a long time, I'm willing to pay a few hundred dollars because I want to create something that's memorable as well as fits into my brand.
If I need a logo for both offline and online, then I'm willing to pay a few hundred dollars too because I need someone that's experienced in logo design for both online and print (offline).
It seems like the OP posted this thread so that he could get an idea of what to charge, if that's the case, I would probably promote my logo services away from the IM market, it's already saturated plus you'll be able to charge higher prices.