This study aims to survey general information from garment factories in South Korea and China, representing, respectively, a developed country and a developing country. Additionally, within the same two countries, the study surveys garment manufacturing costs, from low to high, for a both a “basic” as well as for a “detailed” blouse, pants, and jacket (total of six items), with a goal of determining of an estimation of manufacturing cost in 2018. The results showed that there were meaningful differences between South Korea and China, as expected. Significant differences were shown in the number of employees, monthly wages, effecting factors on the lowest cost price period for a year; garment manufacturing time, and manufacturing costs of basic designs and detailed designs of blouse, pants, and jacket. The results of garments cost were significantly different consistent with the quality, from low cost to high cost, and quantities, from 500 pieces or less to above 10,000 pieces. The overall cost difference between two counties was about 2.6–3.5 times greater (Korea to China). Examining the same item, the difference was larger in low quality and small or large quantity rather than high quality and medium quantity. Interestingly, pants and jackets showed the largest cost difference at quantities above 10,000 pieces. Also, for 2018 there were differences in the estimated costs between both countries. The estimated cost differences were increasing from 2013 giving the implication that future manufacturing cost could increase between Korea and China.