OK, having slept on this, the decision has been made: NO DOUBLE DIPPING.
Tushar, I think you were right to ask the question, and I don't actually think it's greedy to have done so. However, as it is, our (minimal) resource is stretched to the absolute limit to fulfil all the orders anyway - especially the knocking in - and if we're offering 30% but taking 2-3 weeks to send everything out, it all seems a bit pointless to me. The last thing we want is to become another Pro Direct!
Had there been an overwhelming majority wanting to double dip, I may have felt differently, so I was curious to check all the responses, but it seems like the majority is actually against it, which has made this decision a lot easier...