Bank Of Montreal 1931 $10 Note PMG 64 Value?

Good decision. Price way too high thats over $1100.00 Cdn.
Coins of Canada has it listed in Unc 64 as $439.00 Cdn.

I just want to point out that while I agree with @JimmyD (in that the price of the UNC 64 seems high), I would caution you to take C&C (Numista & most World price guides) with a huge grain of salt. If I were to use Numista values, I would not own many notes b/c they're consistently about 60-75% what I paid. There have been several threads complaining about the Numista Algorithm (which determines their pricing table figures) & most of the moderators respond with it is just a figure (not necessarily accurate).
Coinsandcanada I find worst. They catalogue/or table about 80% of what is collectible & forget varieties. I have contacted the admin there & the only thing consistent is that I either don't get a response or the reply is glib (at best). I have just reviewed their pricing tables & compared them to most of my 1935 series (I bought 10 years ago) & they're all LOWER. C&C, Charlton & most pricing tables are dated (old). You're always best off to try your luck at an auction.

Anyway, here's a screen capture of the # that they provide for the 1931 BMO $10.00

Do you notice anything odd? Well, their estimates were last updated in Dec of 2024 (nearly 2 years old).

Do you see what's on ebay right now (below the table figures)? There is an AU58 for more than their C&C UNC64 figure ($503). Although, the note is in a PCGS holder that's a pretty decent price for a PPQ example!