realmaverick - 3:48 am on Apr 13, 2012 (gmt 0)
Don't play with fire.
Competitors can harm your rankings with links. I am 100% certain.
The number of links and amount of money it will take, will depend on many different factors i.e number of links already pointing to the domain.
Though I guess if you're that certain your rankings can't be hurt. Hand your URL over to the guy offering to prove the point. I wouldn't, but if you're so certain and keen to prove you're right, go for it :)