Defendant A’s appeal against Plaintiff C is dismissed.

The appeal by the plaintiffs and the plaintiff A of the defendant corporation

The grounds of appeal are examined.

1. Determination on the grounds of appeal by Defendant A (hereinafter “A”)

A. Since an ex officio judgment on the appeal against Plaintiff C’s appeal seeking revocation or alteration of the judgment unfavorable to himself/herself, the appeal against the lower court’s judgment on the entire winning judgment is not allowed as there is no benefit of filing an appeal (see, e.g., Supreme Court Decision 2017Da246180, Jun. 13, 2019). According to the record, the lower court dismissed the appeal against Plaintiff C that was wholly lost by the first instance court, and thus, the appeal filed by Defendant A against Plaintiff C is unlawful as there is no benefit of the appeal.

B. As to the grounds of appeal against the Plaintiffs other than Plaintiff B and C (hereinafter “Plaintiffs” in this paragraph), the Plaintiffs filed a claim against the Defendant for return of unjust enrichment in excess of the pre-sale price on the ground that the pre-sale price of the leased apartment in this case ought to be calculated in accordance with the standard prescribed by relevant Acts and subordinate statutes, such as the former Rental Housing Act (amended by Act No. 11021, Aug. 4, 201; hereinafter the same shall apply). However, each of the Plaintiffs purchased the leased apartment in this case, on the ground that Defendant A was calculated and paid as the pre-sale price for the pertinent rental apartment in this case.

The lower court: (a) regarding the “appraisal amount” among the elements for calculating the reasonable pre-sale conversion price under the relevant statutes, such as the former Rental Housing Act; (b) on the basis that the Defendant’s Ansan-si requested the Korea Appraisal Board and AL for the assessment of the pre-sale conversion price of the leased apartment of this case, the said two locations considered the “appraisal amount” as the basis for calculating the pre-sale conversion price by taking an arithmetic average of the appraised values for the leased apartment of this case; and (c) on such premise, partly accepted the Plaintiffs’ claim for return of unjust enrichment, and the