We went to John Lewis a few weeks back and wanted to be sold a mattress and we were. The salesman asked our needs, what type of sleepers we were how we slept Etc. and spent about an hour
talking us through about three different mattress's and why they would be good or not so good for us, he was brilliant. Said mattress arrived Thursday and we both subsequently had a brilliant
nights sleep on it. We opted for for a natural, British made mattress. For the record, spring count is 11,000 and materials used; Hemp, linen, cotton, wool, Egyptian cotton, British wool.
My MiL would say buy the best you can afford, a good nights sleep is so important.