Be aware that for some reason Ram chose to put the new heavy duty frame only on the 1-ton trucks and the 2500 still has the old frame. If I was buying a 2013 Ram I would opt for the 1-ton which will also help with the resale value later.
I bought a brand new GM 2500HD diesel in 2011 with extended cab, LT trim level, and every option available including a higher GVWR rear axle, tow package, tow mirrors, chrome side steps, entertainment package, etc. and paid $41,700 plus the sales tax. Others were spending up to $60,000 for similar trucks and the only extra they got were leather seats and the navigation system. Guess who is going to come out ahead after when the trucks are sold 5 years from now.
Dealers make more dollars from the sale of pickups than they do when they sell a full equipped luxury sedan. Lots of profit means lots of room for negotiation if you are patient.