I think that the bottom line here is that Cyclescheme saves a basic rate tax payer in the region of 30% on the purchase of a new bike. A higher rate tax payer will save more.
My employer, for whatever reason, does not want to administer the scheme themself, so they use one of the, "Parasites," in my case, Cyclescheme. Therefore, my choice, and I suspect many other people's choice, is to either pay the full price or to use a cycle purchase scheme and save a healthy sum of money.
These scheme operators, or parasites as they have been referred to, charge the bike shop a commission. Some bike shops (50 Cycles used to. Don't know if they still do) pass that cost onto the customer, some don't. It's the customer's choice whether to accept it and the bike shop's choice whether to participate.
My latest purchase is currently going through Cyclescheme and I will save a considerable sum. I have no difficulty with these cycle purchase schemes.