I know it can be very difficult to select with all of the choices available!
Most carpets have a rating for wear, stain and something else which I can't remember at the moment

Start with a reputable dealer in your area to get an idea of what you like, the quality and the price. Then shop around. You most likely won't find the exact same style/brand at different stores so it can be a bit challenging, but you'll get a feel for what you like and a ballpark price.
Last time I bought carpet I spent a little more to get the type I liked in a size that required less seaming than some others. I also feel installation is important and even though I paid a couple of hundred dollars more than say, Home depot, they took great care with my newly painted walls and did an excellent job.
Tile can be even more difficult. I purchased from a tile specialty store since I felt I got better service and selection than at a huge warehouse style store. I had already chosen a contractor to install, so that wasn't a factor in my selection.
I also have friends who just went to Home Depot, bought the mid-priced stuff and was very happy with it.
Good luck!