They are nice, part of the reason they are common was the super high mintage figure of 36 million. That is a phenomenally high mintage for a coin of the time. Even in WW2 mintages of Florins never got that high (Well 1947 had 37 million, but that was for 2 reasons, one being the silver was debased to 50% and they needed as many of them out to weed out the sterling silver ones still in use, and the second reason was no more were minted until 1951).
Also there was mass specualtion in 1979/1980 when the silver price shot up to $50 an ounce. But even in 1967 when silver prices rose, these coins were hoarded badly and there were almost none left when the base metal coin arrived in 1969.
Because of these reasons, these coins will never be worth over 10 - 25% above bullion unless absolutely SUPERB uncirculated. 99% of them are at least EF and most are AU like yours and even a few low grade UNC. However they will always be worth anywhere between $7 - $12 each depending on the silver price.
This does not stop the dreamers on ebay and Trade Me charging up to $25 or $30 each and rapping on about how its silver and rare and precious!
Even I have managed to accumulate 8 of the darn things.
I love COINS!!!