I have seen this issue rise quite often, “is google against paid links”. Well in my opinion the answer is “maybe yes, but the results show differently”.
The only element I take into consideration is that most of the high ranking sites actively purchase links and have been doing so for quite some time. To name a few: PokerListings, whichpoker, internettexasholdem and quite many more.
It seems that ranking high WITHOUT increasing one way incoming links unnaturally is slowly becoming an impossible task.
Just my 2 cents