I’ve already remarked how much the West Bank reminded me of visiting Israel. I did some googling, and found only a source from 2000, yet it is consistent with my admittedly limited experience (not for Gaza) in 2013:
Most likely, Israeli prices are the upper level of prices for the WBG residents. Anecdotal evidence suggests that the price level in the WBG in fact may be a bit lower than in Israel, especially for a number of non-tradable goods, e.g., housing, and, in Gaza, for some food products, fresh fruits and vegetables. The (statistically significant) parallel movement in the price of level of tradable goods, e.g., food, clothes and furniture in the WBG and Israel, however, generally supports the assumption that most prices in Israel and the WBG are nearly the same.