Have you used their calculator, they can get quite expensive over time.... But they are considered a link network, so if they get busted, and so do you... They will lose, and so will you, assuming they get hit one day....
Have heard about Linksmanagement.. even though they are private, they must have footprints which leads to be caught easily by google. And they are quite expensive too. I'm not opposing but make sure the links frm them wont harm your site.. All the best...
From everything I've seen, when Google finds a link network the sites that sold links get penalized (both the link marketplace + the sites participating), rarely do the buyers get slapped with a penalty. Mix that in with the disavow tool and buying links isn't really that risky (as long as you're smart about where you buy). If you want to play it really safe, buy links to a seperate domain and then link out from that site to your money site.
They seem to be a higher-end link marketplace (with the price reflecting the quality). Depends on whether or not you can get a good ROI spending the money required with them.