Personally I think you should get the best gear you can get...with an emphasis on the best lenses...
I agree..........
If you're going to just take a few pictures of friends and family once in awhile, fine, buy a 3100 and be done with it. But, if you're going to go out and photograph landscapes, wildlife, city streets and people, etc., and try to learn more as you go, and keep at it, then I think you should get the best gear you can get. It will save you money in the long run. The word I keep seeing here is "upgrade", which everyone that's halfway serious is going to do. When you upgrade, you'll probably sell the old gear. You're not going to get the same thing you paid for it, so you're losing money to start with. If you're going from a DX camera, to an FX camera, you're probably going to need to sell your old lenses too. More lost money. You will learn to use the features as you need to. I mentioned in another thread, that I'm a very big believer in: "better to have it and not need it, than to need it and not have it". That's the same thing I tell people that say, "we don't get enough bad weather here in eastern NC. Why did you get 4-wheel drive?" There's been a few times I was very glad I had 4-wheel drive!
