To cans: yeah, that would be a "lot of weed control fabric" and I'm not about to remortgage the house for weed-free acres!! However, if I could only find a decent price (substantially less than £0.40/m sq) I might be tempted to "push the boat out" a bit beyond the few hundred m sq that I presently have in mind. (I'll take a look at Craigmarloch, ta.)
To DavidandCollette: you are right, but I've yet to find anyone advertising for less than £0.40/m sq. Thanks though and I'm sure there will be bulk deals @ a better price if I ring around, but was hoping I could narrow down the list of telephone numbers to call.