I sell covered calls on my stocks, but
may consider buying a massive amount of calls at around $250K with a December 25 expiry. If we end up $300K+ they would be worth a fortune.
the premium's going to be crazy.
I’ll probably be looking at buying so far out of the money that it seems like throwing money away with the expectation for a 300%+ gain next year.

Don’t fall for it!
Actually, what I was considering is selling calls during the bear part of the cycle as an alternative to plain selling coin. I would not sell a call expiring in 2025.
If such OOTM calls for end 2025 were affordable and I happened to have some spare money, well, a little gamble can't hurt right? Worst that can happen, I lose the premium I paid.
However, option pricing is an art and a science. I doubt they would be underpriced, especially if launched in the middle of this bull run.
What I am sure of is: No underpricing will go unpunished
