Need advice on best sprocket for the $

I read a thread a week or two back on ironman sprockets and how people liked and disliked them. I'm looking for a new rear sprocket for my cr and I'm thinking i want to go steel because i want it to last. My bike has very low hours on, still on original chain and sprockets which are all like new. Just going to a 51 rear with stock chain. What is the best sprocket for the $. I'm looking for something that will last and not damage anything. Renthals are pricey and being aluminum I'm thinking they won't last. Any recommendations?

Also where's a good place to buy one. I was looking at the titax sprockets on their site and they're nice. Can anyone offer help?