My favourite B& B site for the UK is: http://www.s-h-systems.co.uk/glasgow.html

According to xe.net, $70USD is about 40 pounds. They list quite a few in that price range including some with AA designation. Sortable.

You might try: http://www.farmstayglasgow.co.uk/

I sympathize with you about London prices. You must spend about 70 - 80 pounds there for two. However, museums are free ;-)

Frances Toronto, Canada