Hi @mp75, thanks for the suggestions! As @irvin mentioned, I have developed discount codes for the next release. There are discount codes that apply site-wide:
... and also individual sale prices for products that can (optionally) be triggered by a discount code.
So the discount codes and sale prices are loosely coupled, they can be used individually or together. I hope this covers your use cases!
As for pay what you want, that's a great feature that I think makes sense along with digital downloads. I will add it to the roadmap, but this will probably not make it to the next release.
If you've been following the GitHub issue tracker, I've been marking a lot of features for version 1.1. I thought I would get v1.1 done sooner, but it looks like that will be a few months away.
In the meantime, I'll make sure I release a new version 1.0.4, which includes discount codes, before the end of March!