This is a common economic problem that was well learned/ exploited with COVID. Everything is on "back-order". Demand goes up and so does the prices. It is an age-old marketing scheme that evolves around making as much money as possible off of every product sold right down to the smallest nut and bolt.
Most filters are readily available from wherever the unit was purchased due to pre-set parts supply contracts for them to carry the machines. No guarantee the prices are not also higher, but they should have them by the case full.
Retailers like Tractor Supply and Home Depot are common service part places. NAPA may also be able to get them at a decent price. Husqvarna does not make the filters, they are a "private label" product. WIX, STP and a couple of others make most of the filters in the automotive and small engine industry.