Hi there
I haven't stayed at these apartments but did have a look when booking my holiday for next Aug. I agree they do look very nice but as you mentioned they are quite expensive. They appear to be exclusive to Thomson in the UK and I know that when I was looking the price for the 4 of us was just under £4k! Have you priced up your weeks on the hotels website
http://www.grupotel.com - I think this works out slightly cheaper, obviously depends on what you can get your flights for though.
Have you been to Cala'n Bosch before? I've been once and am going back again for 2 weeks next August, it's a lovely resort and perfect for families. I've been comparing prices recently and unfortunately the prices are all pretty high for school holidays and much of the accomodation appears to be fully booked already.
Good Luck with your search and hope you get something sorted.