With demand outstripping supply, shops serving tourists have no choice but to buy in at a higher price from local residents, and this extra expense naturally drives up the market price.
在求過於供的情況下，專做觀光客生意的店家，只好出較高的價錢向金門民眾收購，多了這些中間費用，市價必然只好向上爬升了。