Have you manually edited the money in your inventory? If you have more than a certain amount of money the talismans won't spawn. (At least it was like that in earlier versions)
It's still like that, but I do not know whether the money cap increases depending how far you are in the game, or whether it purely depends on the version you're playing.
In the current version, at what's currently the end of the game, the cap is $50,000. If the total value of your money and statues combined is over that amount, then you won't find new statues.
So if you have that much, buy some gold and silver ore, as well as *everything* available on the right hand side of the shop (outfits and quest items), and finally, maybe also some furniture for your house. And then merrily go search for more statues. again.
If you happen to find a gold statue, I think one or two are required for some quest, but you're also guaranteed to find a couple. But, you can always make more with the gold ore anyway, so just trade them for a massage from Pricia, the buff from a gold statue is almost permanent, that's how rare gold statues are. You should actually give Pricia a Jade statue first, then a silver, and then every gold one whenever you find it. (for now, at least, I bet there's still a higher grade statue to be found, not counting the one from the puzzle chest)