History doesn't really give any concrete information regarding how successful a Korean-born player will perform in MLB after going through the posting system. It just hasn't happened very often. Hyun-jin Ryu has been a hit when on the mound, but he's also been hurt a lot. Jung-ho Kang was also pretty good before getting his leg smashed. On the other hand, Byung-ho Park was a massive flop for the Twins.

The thing I wonder about Ha-Seong Kim is if the defensive aspect is real. He's won multiple gold gloves, but is that like in America where gold glove awards tend to be based more on reputation (and sometimes flat out ignorance) than actual performance? If he really can field, a team still can get some value out of him if he plays at a plus-plus level at the shortstop position even if he under-performs with the bat.

Even in a market where I think owners will sit on money and use COVID-19 as the excuse, I would still think earning the right to bid on Kim would run a minimum of 15 million dollars. The last guy through the Korean posting system, Byung-ho Park, cost the Twins 12.85 million for the right to negotiate (to the Korean team) and then Park got a 4 year, 12 million dollar deal on top of that. So that was a 24.85 million dollar investment for the Twins. When Ryu was posted, the Dodgers paid 25.7 million to negotiate and then another 6 years, 36 million to Ryu. No idea what it will eventually cost to get Kim in the upcoming market, but I'm guessing that when you add the fee that goes to the Korean team, that it will be too rich for the Brewers to be involved.