I have the WotC maps from the adventure packs and the Paizo two-sided maps (not the cardstock tiles, but the full-size, markable maps). I also DM Game Day adventures and have those maps. I have them laminated at a Teacher's Supply Store so I can use markers on them also.
You also might want to look for old tiles from the miniatures starter sets pre-map. Half-Price Books and the like may have them or even garage sales.
You also might want to look for old tiles from the miniatures starter sets pre-map. Half-Price Books and the like may have them or even garage sales.