Advantage you gain with X rune versus VII rune is about double of stats - so for example 24 *something* will give you 48 *if the same* etc.
But as vfwiffo has noticed, cost wasn't double (118 DIAS), but 299 - two and half times more.
As for rest of calculation - we all know that x5 multilayer in runes transmutation does not make much sense, thus runes are not used/crafted as much as they should have been. And then in the end, frogster can disable any runes they like to sell.
IMHO, if they leave VII runes at 59 DIAS and X runes at current price, VII will always outsell and make more profit to Frogster.
Vfwiffo, to be fair in comparison, can you make an example for Wrath rune as well? (price now, and before and compare the price

)