I've come to the the conclusion, that non .com domains for flipping purposes are best left to those who are experienced. Stick to .com if you've just started out, it's "easier". If you want to build a non .com sites, that's different (as with prchecker) as it's then all down to the usual content and SEO etc...
Well I am not sure about there worth but yes, within last few month I have seen some .info domain names sold at very high prices at flippa.com. So you can try your luck there.
I don't think those domains are worth much in the .info extension. In my experience only major one word .info's are doing much in the market right now and even those figures are pretty low. .com is definitely where it's at. Concentrate on getting good keyword combination .coms