Lost Rand McNalley sd card

[Winn17TourQD]

So, I took this card out to update. Then lost it😭
Called Winnebago and litz. At first they said I could get one, that they had 17 in stock. 521.00
They called back and said sorry. Since the went out of business they no longer have them.
Sent me to river park , which uses the Nav-go system for 250.00 I went ahead and ordered it, as not to be without something.
Is there a better alternative out there for our systems?