Fee to rise in February
Aspiring Parish Walkers have until the end of the month to make the most of discounted prices for taking part in the event.
Those who enter before 31 January will be charged £30 - or £25 if they are a Manx Telecom customer.
However, after January the entry fee rises to £40.
More than 250 have already signed up to compete in the 85-mile event on 23 June.
Final closing date for entrants is 6 May.