My dad sold books online for many years; he was MrBook on Amazon. Due to age and covid, he hasn’t been selling online the last couple of years.
If there are only a couple of books for sale, then when it gets down to one, the price can go up, because of the dynamics of supply and demand. I have my doubts my dad bothered raising a price routinely, but he definitely sold some books at high price tags. Probably people who have expensive books for sale are very savvy about the marketplace. My dad was savvy, but not necessarily bothering to change prices very often. I think Amazon sellers can set up price changes automatically, but he I don’t think my dad utilized it.
I’d buy one of the cheaper options mentioned above. Maybe your price is higher because you’re in Canada? Can a seller check a box that they won’t ship out of country or something like that? My dad used to ship to many parts of the world, but I wonder if some sellers aren’t willing to deal with it.