A flexible ticket will cost you roughly the most the airline ever might charge for a given route. This is a corollary of yield management: if a flexible ticket would ever be significantly cheaper than the price at any time then it would make good sense for a business traveler to buy up flexible tickets and mess with the airline’s carefully crafted numbers.
So no, you can’t and there’s no way around this. Airlines are notoriously protective of the yield management model, this is why you can’t change names at most airlines for example.
Credit:stackoverflow.com‘