That is the problem: you could attempt to snag a PEY by trying to time their lower prices but if that strategy doesn't pan out, you may end up paying more for either a regular coach ticket or the PEY ticket whose price never dropped--both instead of the cheapest prior option. If you must buy a non premium coach fare buy one that is unrestricted or one whose change cost is less than the money saved by waiting/watching for subsequent better price (kinda what #193 references). For instance, if you must buy a ticket @ 900 units but PEY is currently 950, buy at 900 then watch/wait for the better classes to change: pay 50 units to refund/change original then buy PEY @ 800 (50 less than the original ticket). Aside from timing issues, you may you need to change the new ticket for other reasons and those change costs may exceed the cost of the original. What is your Company's reason for not booking an LCC or the like? It's my guess they want schedule, reliability, and network in exchange for a little cost increase: use the same rationale (productivity, value) rationale for trying to get the PEY bookings from the outset.