I used to know someone who owns a nice hotel by the river in Betws-y-Coed. Weddings are a pain for hotels as most people only want the bedrooms for, say, the Saturday night, which means that they are pretty empty on the Friday. Without the wedding they would probably rent the rooms for both nights or even longer, so they lose out on bookings and have the extra expense (laundry etc) of room changes. Add to this the level of staffing required to properly cater for a wedding party and you're looking at quite a sum. Obviously this gets passed on to the customer, the OP in this case.
The chap I knew in Betws said weddings are such a pain they doubled their asking price to put people off. It made no difference to the bookings, so they doubled it again. This made no difference either, but he's now very happy to cater for them as it makes a lot of money.
Moral of the story ? Either get married in a Register office, hire a marquee and do your own food, or suck it up, pay the money and get a good photographer so you've got something to look at whilst you pay the bills off.