Being in Canada, the idea of test driving audio gear for free is a foreign concept.
Because of that, I don’t think a 5% "handling" fee is unreasonable.
If you are buying within your budget, 5% is not a huge amount for that privilege.
If both parties feel that they left money on the table, then it is probably a fair deal for both sides.
I have never used The Music Room, but they seem to be a very good company to deal with.