You should be ok with 2k, but it really depends on what else you're planning on doing. Are you renting a car? Shopping? Group tours/trips? Do you like to spend lavishly? :)Hard to say, everyone is different. It's easy to spend money!
Not renting a car. Planning on trip to Warsaw (train), Auschwitz and Salt Mines as well as any other tours of the city, plus some sightseeing. Oh, and a purchase or two from the Hard Rock Cafe!!
We do spend, but not too lavishly...decent food and drink throughout.