The Osbon pump that is covered by insurance is $525+, and because of distributor squabbles, I appealed the cost got mine covered as in-network, and paid only the shipping/handling fee.
Some cover it as out-of network, so perhaps 70% ?
And as a prescription medical expense, it falls into the deductibles for taxes if one itemizes, as well as FSA/HSA plans.
But it does have a long term warranty, so in theory you don't have to replace it.
I'm not really getting good vibes about buying that sort of thing on ebay.