A nice little site, they sound enthusiastic and they don't look like ripoff merchants. I imagine Czech property prices may have become even more affordable in the past several months.
The Czech Republic looks like a delightful place to visit, perhaps to live. Here's an interesting blog written by a British woman who took the plunge into Czech property. If you go to her profile you'll see links to her other blogs, which are also interesting in this context, and from there there are also links to other Czech property blogs and ones on Cesky Krumlov in particular.