Hi - we went to Warsaw a couple of years ago - like most of Poland food, drink etc.. is pretty cheap �1.20 to �1.50 for a beer, �10.00-�12.00 each (less in some places) for an evening meal
As for were to go the Old Town Market Square is very pretty, the Royal Castle is very interesting and I would definately recommend visting the Monument to the Ghetto Heroes and the walking the Path of Remembrance - really quite moving. St. John's Cathedral is also a peaceful place to visit, as are some of the partks and gardens (qweather permitting) and the Palace of Culture and Science provides an iconic though controversial image.
Do try and find some postcards, picyures of books showing the devestation of World War II compared to the restoration of the city as it is today - amazing.