Flash offer for spell upgrade

So I get a copy of Ancestral Ferocity - Rare - and get this flash offer

I already have a copy of Ancestral Ferocity - Epic
And since it’s a spell, there is no possible benefit to having a second Epic copy (no attributes, so every version of the spell is the same)

Now I was NEVER going to buy an upgrade under this pricing model, however for those who would be interested in flash offers, perhaps making sure the offer provides some value would be an important consideration (I think this issues is specifically for spells since they don’t have attributes)