Different registrars have different prices.
Typically variety of ccTLDs is inversely proportional to $$$. In other words the more ccTLDs they offer the more you pay for each.
I was the first Employee of NetNames (
http://www.netnames.co.uk/), the first company to specialize in ccTLD registration as a service for corporate customers back in 1995. It is basically a big big hassle that costs a lot to deal with all the NICs around the world.
At Dotster we offer basic European ccTLDs as well as the usual .nu/.ws/.cc etc for a price lower than any other major registrar, but at the end of the day if you want the cheapest price you need to go with an ISP in that country.
Mark......
(in a personal capacity)
P.S. Off Topic Comment: At one time I managed more TLDs than Verisign or neulevel ever have done, I was operating 5 different ccTLDs (including my favorite: .TM)