Umbrellas are not as widely available in Cluj as they might be in Amsterdam, but you can still find them if you know where to look.
Supermarkets
Kauflaud. A nice variety of reasonably priced umbrellas. We saw some around 35 lei and up.
Carrefour (and Carrefour Express). Here you can find compact umbrellas by the checkout line. approximately the same prices as Kaufland.
Drugstores
DM
Museums
The Transylvania National History Museum (MNIT) has a lovely orange umbrella. You won’t get as much rain as Amsterdam, but you can still wear orange in the rain!