Just ordered a Custom Frame bag from this place £38 delivered! Always like to share a cheap deal.. :D

http://www.buggybags.co.uk/pages/BikeBagOptions.htm

Will report back once it arrive which should be any time

Had one a couple of weeks ago - not used it yet but it's really well made and I'm very pleased with it - hopefully using it his weekend with my lad (his first bivi) in the Beacons

That sounds good, you'll have to let us know how you got on. :D

Used the buggybags frame bag last night for the first time. It was olny for a short ride up the Brimore tram road from Talybont up to a bivi site overlooking the reservoir but I was carrying a fair bit of extra stuff for my son.
The frame bag was great - well made and able to carry a lot of kit - the mapcase option was useful but with a w/proof map it did stick out a bit - no probs with a standard OS map though. For the money you really can't go wrong