Mortgage Fees

Why is it some mortgages carry 'booking fees' and others don't? And perhaps more crucially, why do they cost sums like 499GBP or 999GBP. How can banks justify the charge? What's it for? Someone enters a few details on the computer and you charge nearly a grand for it? What is it about the mortgages that don't have fees compared to those that do? It seems the lower the interest rate on the mortgage, the higher the fee. A back door way for banks to recoup some money methinks. Remind me again why so many people don't like banks?

Now that Stamp Duty has gone, fees have risen to the top of my list of annoying things about buying a house. When I finally get around to arranging a mortgage, I'm going to refuse to pay any fees. If my bank doesn't like it, I'm moving all my accounts and savings the hell out of there and into a bank that's a bit more reasonable.