Multiple bids above asking - How to win property?

[John S.]

A duplex property came onto the market for 200k yesterday.  I went to see it first appointment at 8am and submitted an offer at asking price.  My agent said it's in an estate and we'll need to wait for 3 approvals before the contract gets signed. 

The property is brick, built in 1980s, 3 bed 2.5 bath in each unit totaling 6bed/5bath.  Typically these are sold separately, but this property is unique in the sense that the owner owns both and selling them together.   Individually the "zestimate" is $256,00each...totaling about 500,000... Let's assume they're worth about 350-400k total. Why would the listing for the entire property be so low?..

The next day (today) my agent came back and said that the selling agent mentioned multiple offers... Should I change my offer something like 215,000 with the option to beat the highest offer by $500?  Should I include a cap in an offer like that? I feel like offering something like 300,000 would make the seller question the list price and reevaluate the entire sale.