It depends on the time of year and where in Spain you are planning to visit, and Dollar- Euro exchange rates (the peseta is tied to the Euro, so if the Euro strengthens, your dollars (or Pounds sterling) buy less).
Keeping those things in mind, try
http://www.hotelsearch.com to get some idea of what lodging will cost you.
As for meals: Figure on 300-to-400 pesetas for breakfast (coffee & churros or toast), for midday (main) meal you should be able to find a menu del dia for 1,200 pesetas or less (in Campello, for example, there's a lunch area in the supermarket where the menu del dia is about 900-pesetas; and in Bilbao, on a sidestreet near the Guggenheim I found a menu del dia for 750-pesetas). Evening meal (snack) can consist of tapas.
[This message has been edited by Eddie (edited 01-03-2001).]