Ermintrude - I use the travel agent linked to my Goldfish credit card (they're called Travelcare Direct).
As a Goldfish card holder they give me a flat 6 1/2% off the cost of any holiday. If I pay using the card I don't have to pay the 2% credit card 'handling fee' that travel agents usually charge. The card gives me 'points' which I can spend on Argos, M&S vouchers etc.
I've asked in another thread 'how to get the best discount' and someone else does a similar thing through their own card company to get holiday discounts.
Did you know that TC also have their own credit card, costs nothing to get one and at least it'll mean you won't pay the additional 2%, as long as you have some self discipline and chop the thing up after paying for the holiday! Personally, I'd get a Goldfish card.........................