It's only fishy if it's not explained very well. People are used to seeing large discounts in downloadable products already. It's not uncommon to see 70% off sales on Steam, Unity Asset Store or Udemy and they work very well for the buyer and seller.

The only difference here is asking people to pay with Bitcoin. That's the hard part. I actually think a lot of people would be curious enough to want to try Bitcoin especially if they feel like they're getting a good discount to do so.

However, the instructions need to be very clear and their concerns need to be addressed. Probably to the point of walking them through every step. Most people won't bother if they have to figure it out themselves.