To avoid surprises, check with your bank and/or credit card companies to see what they charge to use your ATM or credit cards. (My VISA/MC charges 3%.)
Credit Cards: In many cases it’s easiest to make purchases with a credit card. If you choose to use credit cards, tell your credit card company you will be in Israel so they don’t stop your card while you are trying to make a purchase. Not all vendors accept credit cards but if they do, most cards are usually accepted.
Cash Machines: You may find it easiest to use your debit card. Remember to check with your particular card for fees that might be associated with using it.
Cash: You can exchange money at the airport. The exchange rate is usually pretty darn fair. No need to exchange any money before you get there. Other groups have suggested you’ll likely spend about $500 (shopping, food, tip to guide and driver, plus a little of this & that, etc…)