Oh sure. You could wear your blue jeans and Hawaii floral shirt. But if you want to look like you belong and get into the spirit, these street vendors are in many locations. Note that some folks wear their whites a few days too many.
What to buy: White pants and shirt, wtih a bull saying on it. Add a red hankerchief and sash and you are off to the races.
Mercado Publico de Santo Domingo or Public Market of Saint Dominic was established at that place on July 4, 1565. Today you can buy any kind of agricultural products produced by local farmers. There are meet and jamon, cheese and wines, beer and cider, fresh vegetables and fruits there, otherwise you can buy whatever you need to eat and drink. There is also food and grocery shop in the market.
From Monday to Saturday, from 08:00 to 14:00.
Friday: from 08:00 to 14:00 and from 16:30 to 20h.
What to pay: Depends on your purse
Most of the shops in Pamploma are attractive small and privately owned, I wasn't aware of any of the big chain shops whilst walking around. There may be some I didnt see.
But Corte Inglès has everything you'd expect from a giant department store, including giant prices.
I would say bring your own white pants and buy the t shirt and scarfs here, they cost about $10 each