Buying Straw ...
in our area, not a problem, we get ours from a friendly Sheep Farmer who uses it by the truck load for bedding during Lambing season (right now). Last year we paid 50p per square bale of Wheat straw. This year we paid £1 per bale for Barley straw, bought 10 bales.
Another possible source is Horse stables, or anyone keeping Horses. Although many have moved to wood shavings for stable litter, there are still a lot using straw and chopped straw.
Our local Newspaper regularly advertises straw for sale (square bales) at around £2.50 per bale.
Mikey