We can do Manchester cheaper from Birmingham in the same way as Sheffield. For Sheffield we get the off peak return to Derby then use the Wayfarer scratchcard ticket to Sheffield. (Buy them half a dozen at a time as we like Sheffield!)

Not done Manchester the cheap way before, but it is I believe an off peak return to Macclesfield then a wayfarer type ticket for Manchester. We usually stay in Bury for Manchester so not tried the train trip. It is amazing how much cheaper these alternatives are.