Why would the visa be the same as it always was? If it used to be £10.00 and is now charged in dollars and at today's rate is 5 pence short of £51.00 for a family of four it's an increase. If a family chooses to compare prices with other countries which don't charge a visa fee then it is, IMHO, a valid assertion that visa fees are a reason, albeit in small measure, for a decline in Turkish tourism.