Why would the lender post an opening bid that is substantially higher than the value of the property?

The lender can discount the opening bid or add the additional interest that has accrued on the loan to the published bid. It is impossible to know for sure which lenders will discount the opening bid. Oftentimes the lender is the servicer of the loan for another investor and the opening bid is set by the actual investor. There could be additional interests involved, like the existence of a Mortgage Insurance policy. This may cause the lender to set the opening bid at the full amount owed on the loan.