You can also buy fresh frog legs from Singapore's frog farms. You can make that an excursion trip, or if your husband thinks farms are no good for his expensive tyres (haha, no kidding, I heard that before), then just ring them to order and they will deliver to your home in a icebox, cleaned, packed, chilled. Price was around s$10-12 for four or five.
Yes, Sheng Shiong is another good place. But I think the pricing is more attractive when on offer as it can go as low as s$2.20 per frog.