There are two main factors to consider:

Not all of the funds collected in the NFT’s price are used to finance the affordable housing project. Some of the NFT’s value relates to the artistic, collectible and utility characteristics of the NFT. While those features will be valued differently by everyone, it is non-zero when considering the NFT’s resale value. There are also costs to Empowa in the implementation of the NFT
Sale that need to be covered.

The EMP exchange rate negotiated with Casa Real for their repayments does not match the spot price of EMP when an NFT was purchased. Despite the fact that the EMP spot price will vary over the duration of the NFT sale (11/07/2022 – 08/08/2022) depending on when it is being purchased, the lack of liquidity for EMP on spot markets at commencement of the sale means that a fair price for the amount of money being raised (over $300K) would be much higher than the spot price at that time.This was tested by evaluating the price that would have been given if purchasing 100,000 ADA worth of EMP on Minswap, where the most liquidity was held at the time. As the price given would have resulted in considerably less rewards than currently offered, a price was negotiated in between to make it fair in relation to the current market, while still making it attractive to NFT purchasers.