Good article. The first two hotels they mention are VERY expensive for Krakow but as they say no more than many other European cities. I have heard that prices are starting to creep up there, as it has now become very popular for weekenders/stag & hen parties, which is a shame but inevitable.
As for airlines, I only heard about this one recently
Wizz Air
Very low fares, although flights from Gatwick are very late in the day. Worth a look.
I'm hoping to make a visit prior to the challenge, if I do I'll gather lots of info to post up here.