A while ago I had the jones to get a gun and couldn't find one locally. I went to Bud's Gun Shop online and had a great experience (budsgunshop.com). They have Ruger SP101s for $474 (cash) or $488.22 with a credit card. You would have to pay a FFL dealer to complete the transfer (about $10). I agree with your call on Bass Pro Shop. Nice store but their prices can be high and for me to drive downtown to not find what I am looking for in a store that size is frustrating.
Regarding an alloy or poly gun (like the LCR), if you were only going to be using snakeshot and/or using the gun for a BUG they are great. I agree that shooting 357 loads through an alloy gun is no joy. If you are want a revolver to throw mag loads and/or just a lot of rounds down range, going with a heavier wheel gun makes sense. This is one of those great choices that you can't go wrong either way.
The last 3 times I have either gotten little to no help from bass pro, or have been blatantly insulted by their staff. Literally. Yesterday the archery guy called me a moron for buying a PSE bow. I have been outright ignored at the gun counter, with 3 associates standing there and the place being dead to boot. And the employees there 90% of the time don't have a clue what they are talking about. Not worth my money.
With reguards to weight, I am looking for something that will last me the next 20 years of shooting magnum loads at the range, carrying on my person, and shooting snakes hot through. Just an all around firearm. I figure a standard/heavy model is what will suit me best. Honestly, the weight doesn't bother me, my XDS 9mm isnt exactly light for its size, and I carry it almost every day and don't mind it one bit.