That's about what you should expect to pay for Weatherbeeta. You got a medium weight, rain sheet and fleece cooler. Blankets have gone up drastically in price this year, but like Jaydee said you can find them used or from closing stores for cheaper. Personally I would never pay that much, I own a fleece cooler, rain sheet, medium weight, and heavy weight all paid for less than that set, but again only one is a weatherbeeta that I bought dirt cheap because it looks like a disco ball threw up on it.
I also much prefer a 1200 denier, but if your horse does not get picked on or leaves it's clothes alone you should be fine with 600. I would never go less than that.
For future reference plan ahead, get blankets in spring when stores are trying to sell off their remaining inventory.