Handed his chance in English football in January, the 25-year-old Irishman netted 9 times in 22 appearances for a Darlington side doomed to relegation to the Conference.
His displays against Northampton in particular persuaded Ian Sampson to make a move for Purcell after the departure of Adebayo Akinfenwa and the bookmakers are backing a successful season, pricing Purcell up at 18/1 to be the top marksman in the division.
Purcell told BBC Radio Northampton recently: "I knew the set-up here and it looked like a good club, somewhere stable where I can enjoy myself.
"Darlington was my first chance in English football. I made a little name for myself there and hopefully I can make a bigger name for myself here."
The man he has replaced at Sixfields meanwhile is also fancied to have a good season despite not yet signing for a new club.
Akinfenwa, tipped to join Southend United shortly, is 14/1 to top the scoring charts in League Two.