That is complicated.
Since the funds are converted from USD to GBP (British pounds), there is an exchange rate. I bought it for $330 USD, but because of the great exchange rate at the time, if I were to get a refund right now, I would only get $280 or so.
The second batch will cost more. This batch is basically a "beta testing" batch, and they are actually LOSING money on each unit. They will cover most of the R&D costs, though. The next batch will actually put them into profit, and it is looking to cost between $350 and $380.