LN2 is actually pretty cheap. Well at least when you get into dealing with chemicals. If you're just doing Benchmark runs, i'd suggest getting a decent pot. I've been out of the loop for a while now. I would suggest going over to Overclockers.com. Ask For I.M.O.G. He's a moderator there, He'll set you on the right track. He does competitive over clocking. Most of the guys over there do.