There is currently a huge difference in price between the top few PUNK NFT, and the bottom few. For instance, the lowest ask price is currently 63.66 ETH ( as of the time of writing this report ) as seen here. The top few NFTS are last sold in the range of 1000s of ETH. 
Since the value of the debt that a user can raise from the collateral is computed by the total number of deposited collaterals multiplied by the lowest price of the NFT in the collection, it makes little sense for anyone to use any higher-valued NFTs as collateral. This seriously limits the use of the protocol if only a limited number of NFTS are used.
It is recommended that we use a different metric to measure price here. We could target NFTs individually instead of seeing them as a group.
