Check out typical prices for their stuff first, comparing perhaps to Makro (where you don't pay anything for membership but have to prove you run a business). Nevertheless the place always seems full of people who evidently aren't in business.
Sounds like a waste of money to me. If you live anywhere near a Costco warehouse operation and have the qualifications for membership, you can pay a subscription of �20 a year, buy in bulk and save a considerable sum of money. Any organisation which charges �70 just for membership starts off with a huge handicap for those who join and I doubt whether you would save any money at all.