Well, it comes from the same series as the medal in the link; it's the same basic type. And it certainly would have been made and sold before the coronation of the next king William IV in 1831, by which time coronation medals would have been sold instead.
There are numerous varieties of this medal (including the one with BRITAIN mis-spelled); that means numerous dies were employed to strike them, implying that the total mintage for the type would have been quite large. As such, I would assume it would not be particularly valuable.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis