I bought a tape core on Amazon. My neighbor threw away on of those nice heavy tape dispensers, and I couldn't find the core, since it probably fell out and was buried in the damp garbage (I try not to actually go through yucky wet stuff). Amazon has those cores for around two dollars with free shipping, so i ordered one. I've always wanted one of those big dispensers, so this is nice.
They also tossed a nice heavy-duty stapler and a lot of desk organizers. I don't get people. There's a thrift store just down the street.