Copying from another thread i posted in but: "Just updated to the latest version and haven't tried importing anything new but not having any pricing issues or add to cart issues. I am using the Woo version and had to update my theme also because of code not compatible with Woocommerce 3. Hopefully
@Yaros and team will test thoroughly and quickly release updates if required."
Edit: Sound like most of the complaints are because of the change in Woocommerce:
Variable product prices which contain sale items will no longer contain a strikethrough.
Edit 2: Tons of fixes in the new 3.0.1 Woocommerce update. Including:
* Fix - Show a sale price on variable products if on sale and all prices are the same.