Out of pocket is the same with or without insurance?

I'm in USA, with Medicare. I got a call today from nsm telling me they're about to submit the chair order (tilite aero t) to insurance, that my estimated out of pocket with Medicare is $2230, which is the exact same cost as online stores that don't use insurance. Is this normally the case? I feel like it's silly to wait for approval if I can pay the same and get it much quicker.