How much would you purchase advertising on a CPC basis for Webmaster traffic?

Hi,
I have just come up with a few ideas and was wondering that if you paid for a "featured listing" spot on a webmaster type site, how much would you pay per click or thing is reasonable. Would you think something like $0.30 – $0.40 CPC is a good price?
Also, what about putting advertising in the signature space of a webmaster forums, how much per click would you pay there? Would you pay around $0.10 – $0.15 CPC or would you think that is a good price?
Thanks!

Original post by john269