Visiting Munakata, Fukuoka Japan

We drove to the city of Munakata which is in the prefecture of Fukuoka , 26 km away. The population of Munakata is about 97,000 and the area is 14.5 times the size of Toa Payoh, Singapore. Toa Payoh has a population of 125,000.
Shopping is rather expensive and so we did not buy much things from Munakata. We had lunch over there.
On the way we stopped at a stall by the roadside. It was advertising a watermelon was going for about S$6. When got there, we were told the small ones (only 3 left) cost 500 Yen or $6 and the rest cost from 2,000 Yen to 6,000 Yen. Ridiculous, too expensive! and so we left without buying. Could have easily got the big ones at a supermarket for 1,000 Yen ($12).