Kraków, definitely.
I've been offered all sorts of slightly convoluted drinks-plus-services deals that I've always turned down because it hasn't been entirely clear what I would be getting - and, although things are generally pretty cheap, they were at the more expensive end of local prices.
However, I've also had strippers go for my fly within the first minute of a private dance. Now, bear in mind that's not necessarily incredible value (I assume the calculation is that, once she's got her hand in your shorts, you'll keep paying to extend the dance for as long as ... necessary, which would work out as a pretty hefty hourly rate) but I found it pretty exciting and, when I was there more regularly, I'd often go down this route for a bj (particularly as I found it a bit difficult to make ordinary punting arrangements there). Clearly, it's not every dancer that will do this so, unless you are regular and get to know one or two that do, there's going to be an element of luck required.
The best option I found, though, was to arrange to meet one of the dancers away from the club, which was a surprisingly regular offer. The first time it happened to me was on a fairly quiet night and, after a couple of dances, we had to move on to meet friends elsewhere. The girl I was talking to told me to come back at the end of her shift and for (something like) €150 she would go back to my apartment.
Now, I was a bit sceptical when I ventured back (and fairly sure I had stayed relatively sober for nothing) but there she was and I got what I suppose you would class as an overnight, if it hadn't been from early morning to early afternoon, at incredible value. Probably about three hours of services in total, either side of about five sleeping.
Never quite so lucky again, but still fairly common to take one of the girls home for an hour or so at the end of the night and, for me, having had a few dances from them beforehand certainly adds something.