Do not buy antiquities here, as they are most likely fake. This is the center of the fake coin industry. Insist on a certificate of authenticity, and pay by credit card and keep your receipt. At least then you can charge back the dealer when you learn you have been deceived.
You will probably also be touted some yellow Hezbullah T-shirts while you are at Baalbeck, as it is the birthplace of that party. If you choose to buy one beware: these T-shirts will self-destruct in the laundry, losing all of their green ink in the wash. That aside, they are an interesting souvenir. They should only cost 1000 LL, not the 15,000 LL you will be touted.
