Hiya. Yes, I am in England. I just searched for "custom wedding cake topper" and started looking at the various sites. It wasn't cheap, that's for sure, but nothing custom made ever is. It was about $150 USD, and she was one of the cheaper sites! (We're not having a big wedding, so felt we could "splurge" on this item. It really depends on what you want. If we didn't have the plaque at the bottom with our names and date, nor the flags, it would have been about $30-40 cheaper.
It took about 3 weeks, but I did notice that other sites said you had to order 4 or 6 weeks ahead of time. Some were booked throughout the rest of 2011!