I can't personally recommend anything in that price range but asiatravel has quite a few places that could suit.

I'd have a look at their site (and maybe a couple of others) then go to a site that has reviews - sawadee or hotel-travel - and see what other travellers have to say about the place.

On the old travel site there were quite a few recommendations for guesthouses. There were quite a few at Kanchanaburi but I can't remember the names. If you can get onto that site, just do a search.

Is the old site still able to be read Mark ?