It is a bit peculiar with the high prices. The bottom line stays the same, as there are no cost of sales, only overheads. You can put through a lot more (in prep) of low priced items as they need less consideration towards pricing. I would say that revenue benefits more from high throughput at low prices, than low throughput at high prices. I should imagine it's also more fun for the volunteers if there is a lot of throughput, although the odd individual comes and volunteers to sit around and natter and rather sees customer leaving than coming in, most would like it to be a bit busier, I'm sure. Doesn't mean you shouldn't price a whole le Creuset set appropriately, but most of the clothing items would benefit from a one-size-fits-all pricing.
I think the rummage boxes are a really good thing, a v low prices (20p items and such). Both for bric-a-brac and for clothing items.
I haven't seen anyone mention the rotation. I saw a few mentions of a coat or other item being in the shop for three months. That didn't happen at the Cancer Research shop I volunteered for a while at, more than 15 years ago. Daily, new stuff would hang out, the labels had a date on, and the older stuff (2 weeks, I think) would go to the back to the swap out rail. That rail would be bundled into the van, once a week, to be swapped with the "old" stock of a different location (usually a fixed pattern). Some stuff would sell in some places, not in others. If it had been in two shops and not sold, it would be ragged, £1 a bag or some such.
No, I don't want to pay £2.49 for a second hand paperback, unless I really, really want it, it was the last in a series I needed, or something like that. Otherwise, I'd prefer it new, actually.