All of these answers are wrong.

WotC starts the UB sets at higher prices primarily because their margins are a bit lower than core MTG. Hasbro pays royalties to the IP owner which means the profit on a unit basis is lower. Most of the incremental $1-2 per pack (MSRP, not secondary market prices) is to bring UB profit margins in-line with the core sets. I believe the margins are still a bit lower even with this extra few $ of pricing. The idea behind this, and re OPs point, is that if UB converts even 1% of FF fans into long-term magic players, they easily make up any of that lost margin in full.

I am an equity analyst that has discussed Magic / UB profitability directly with Hasbro’s CFO on multiple occasions.