Find a different store. Grinders are not prohibited, not for import nor for sale, and if he's feeding you a BS story like that in the internet age, he's not an honest businessman.
So i went to my favorite shop in town to buy a new grinder and was told that the feds have recently outlawed the import of grinders with pollen catches. Was wondering if anyone else has heard anything about this?
Sounds ridiculous, and I don't know under what law you could make pollen catchers in a grinder illegal, but my advice is to forget about the pollen catchers. In my experience, they're useless. You pay 20 bucks extra for a grinder that's actually more annoying to use than a standard, single-layer one. Even when you don't open up the bottom layer, there's two "floors" you have to separately open when you open up your grinder and empty out the herb. Waste of time. Also, the pollen/kief that gets caught and stored in the bottom? Pretty useless, it takes ages to build up and is worth a couple of hits.
Also, a standard grinder collects the pollen just as well - rinse it out with alcohol or grind damp tobacco in the grinder to get the resin off from the insides.
I had one for a long time but when it got taken by the cops I had no intention of buying another one. I'm much more satisfied with my $3 plastic grinder.