Stumbled across some Ritchey 406x33 tires, roughly Primo Comet sized
while going through the online Nashbar catalog a few days ago.
Priced at $10, ordered two, they are wire rimmed but fairly flexible
and foldable. Tread is a bit more aggressive than Primos but still looks
ok for road riding. It appears to be unidirectional. No kevlar at that price.