I disagree that tube rolling is pointless. Even if you believe there are no longer any good old tubes available, there are usually several new tubes to try. There are no lending programs however and as already stated the only way is to buy and try. You can sell what you don't like. Just because you didn't like the sonic of a particular tube it does not mean it is a bad tube, just not your taste. I happen to believe you can get some good old tubes but the price is getting extremely high.
How do you test different tubes?
I hear people recommending different brand of tubes for amps, preamps, etc. My question is how are people doing this? Are there dealers who loan tubes like other gear? I would hate to have to purchase different sets of tubes, try them, find the one I like best, and then trying to sell the set I don't like.