Assume most of the bike shops just agree to suck up the 10% 'admin' fee cycle scheme seem to be charging them on the understanding that cyclescheme is a major driver of business and the margins on non-sale stuff are big enough to absorb it anyway.
That's exactly what this store says. For customers like me I think they know I will shop around and get what I want so there's not really any incentive to sell me a sale bike and take a hit on it.
Ribble charge an extra 10% for any cyclescheme purchase I seem to remember.