I too have been wondering how much to buy, how much I will actually need for one quilt of small hexagons (and no, I don't know what size quilt! Something 'bed' sized but maybe a single bed would do to begin with ...)
However I've only been buying one metre (a yard and 4 inches) as the equivalent of 4 fat quarters ... 2 metres when I've really loved it or think it's going to be a high proportion of a design combination, and 1/2 a metre when i've suspects that I'll only need four or five hexagons, but I don't think the fabric shops cut any less than 1/2 metre ....
The classified section has been great for me - as I have a couple of ladies sending me and envelope of scraps, in one case about 20 different fabrics with at least 2 hexagons worth of each ... in exchange for fat quarters of scandinavian style fabrics. I think this is SO SO great! I will get the small amounts of a really varied range of fabrics that I need and I am supplying them with something they really want rather than just paying out all the time ... I have bought some fabric, from this board, using Paypal and I'm looking forward to it but with nowhere near the thrill of the 'Fabric Swap' parcels!
Helen