At the Front Desk office, you'll find a souvenir shop. You can buy items you might have forgotten to bring, or anything you just fancy to buy for yourself.
What to buy: Montemar souvenir t-shirts, beachwear, sun dresses, intricately/uniquely designed beach bags
What to pay: Depends on what you buy. Quite pricey for the quality, though if the item makes you happy and look lovely, then go! My daughter bought a sundress for P3,940 (about $84) and a top for P945.60 (about $20). I wouldn't spend that for myself.
A kiosk-type gazebo at the beach front, very near the restaurant sells souvenir items like shell craft, pearls, beach jewelry, decors, etc.
What to buy: Personally, I found the items being sold very expensive so I didn't buy anything. Some items are being sold at Subic for much, much less. Polished decorative shells were also being at high prices. The vendors said they come all the way from Olongapo City, and pay Montemar for rental of the place so they have to raise their prices.
What to pay: For example, the bracelets made of chipped shells were sold at Subic for only P50; at Montemar, they sell it for P250 negotiable for only P200, but still expensive.