Dunno about the charity side of the biz, can't speak to that. This is strictly about the shops. The prices CAN be high, but the items are quality, so I believe it's a fair price. I was looking at a solid wood armoire for $300 which was a bit shocking until I looked at the same thing online at over a grand. There are high quality items here and they're priced accordingly.
On the other side, if you're looking for bargains, they're here also.
I found a pair of CCM hockey skates, well sharpened and that fit me for $3. it costs $10 to sharpen a set of blades to I'm already $7 ahead and got a free set of skates. I bought handfuls of seeds (packed for 2018) for ten cents each. I did a lot of my end-of-the-world shopping in the seed bins. The skates will come in handy when Phoenix freezes over this August.
Overall, the place is fun, clean and well organized. If they sold Swedish meatballs it would put Ikea out of business.