I have used 4 brands now of mineral makeup and I would rate them like this
#1 - Halo- Smashbox (incredible)
#2- Sheercover - lighter and more natural look than Bare minerals
#3 Bare Minerals
#4 - Loreal - I used this for 2 days as I forgot my sheercover at home on a trip and needed something cheap - ok, but wore off in about 5 hours. I looked spotty by lunch each day.
I think you truly get what you pay for based on my mineral make up experiences. If you have never tried mineral before, starting with Loreal would be a good idea, just to see if you like the concept even. If you go to Ulta though, they will let you return makeup you don't like. That is the only reason I shelled out almost $60 for a container of smahbox mineral foundation. I tried and loved, so I didn't return it, but it was nice to have the option.