1. According to the reasoning of the judgment below as to the ground of appeal No. 1, the court below found that the amount paid by the plaintiffs in excess of the legitimate sale price calculated by the defendant for the basic living facilities installation costs is unjust gains, and then the amount actually paid by the plaintiffs AA, AC, A, B, Network AE, C, D, E,W, BG, and F (hereinafter "Plaintiff A, etc.") includes overdue interest accrued due to delay in the payment of the sale price, but it can be found that the defendant calculated unjust gains by deducting the legitimate sale price from the paid amount including overdue interest from the above plaintiffs.

However, in the case of overdue interests arising from the delay of the purchase price paid by the Defendant from Plaintiff A, etc., the part corresponding to the legitimate sale price is attributable to the said Plaintiffs, and thus, it cannot be deemed that the Defendant gains without any legal ground. In so determining, the lower court erred by misapprehending the legal doctrine on the calculation of unjust enrichment, thereby adversely affecting the conclusion of the judgment.

The ground of appeal pointing this out is with merit.

2. Regarding ground of appeal No. 2

A. The lower court determined, based on its adopted evidence, that the Plaintiffs, BE, BI, BJ, BK, BL, BM, BN, BO, and F (hereinafter “PlaintiffW, etc.”) transferred each of the lots of housing units sold to a third party after paying the purchase price to the Defendant, and that there was no circumstance that the said Plaintiffs comprehensively transferred their status in the sale contract to a third party, and that the said Plaintiffs can claim restitution of unjust enrichment to the Defendant.

B. However, in light of the following circumstances, the lower court erred by recognizing facts in violation of logical and empirical rules, thereby adversely affecting the conclusion of the judgment. The allegation in the grounds of appeal assigning this error is with merit.

1. The record.