I would imagine it would be in the interests of the club to want to secure sales as soon as possible, for the same sort of reasons as clubs price tickets to encourage fans to buy in advance.
I doubt there would be a two tier time-based pricing system for a Play Off semi-final with tickets on sale for just a week or so. I may be wrong, of course, but doesn’t ‘this kind of match’ just have the one ticket price (concessions excepting) per each relevant area of the ground?
