Most directories are not worth being listed on and certainly not worth the money in my opinion! Who uses directories anymore? Maybe some folk's still do, but like Eduardo says, make sure it's a "no-follow." Surely your money could be better spent elsewhere?
"Do paid directory links violate Google guidelines?" I'm going to have to say, yes! And I'm saying yes to "no-follow" links to - why? Purely on the basis that your practically throwing money away!
Any links intended to manipulate page rank or a site's ranking in Google search results may be considered part of a link scheme and a violation of Google’s guidelines.
You can find further information here.
https://support.google.com/webmasters/answer/66356?hl=en
Hope this helps?
Gary