In reply to MrRiley:
Thank you that is helpful. I have been advised to try on the crampons with the boots, but to be totally honest I do not know what I am looking for, and I have grave doubts that the staff in some shops do either. Though I do know some who would.
I can buy these online next day delivery £132 which is a lot less than I can buy in a shop, so my worst case scenario is to sell secondhand after trying for a bit.