Builders (new door and frontage) went off and bought, as we requested, a new door bell. On the invoice they've put it down as a couple of quid more than they paid for it at a local store (I know cos I checked wanting to see some instructions and, intrigued, rang store which confirmed the cheaper price). They now want the balance, including the cost of this doorbell, paid.
Of course, they must be paid but AIBU to worry that if they've diddled us over a couple of quid, they might have slightly exaggerated other costs? The estimates and invoices are quite detailed but there are no costings other than the grand total (which is a lot). I asked them for the bell receipt in case something went wrong with it and they said I'd get it in a month or so as they have a trade account with the store. In my email, I referred to the price on the email - that wasn't corrected by them in their reply.
Should I bother to ask them to confirm the price - should I stump up - should I deduct a couple of quid off the invoice. I hate to sound petty but then I don't like being taken for a ride. Thanks for any thoughts!