How to negotiate around packaged listings from the seller?

[Jake Jajack]

I would like to make an offer on a small multifamily property but the seller has packaged the duplex with a commercial building he is also trying to sell. The properties have been priced separately. It's been about 2 weeks since this property was listed. 

I had conversations directly with the seller and realtor and expressed my interest in buying the duplex only. They said they would keep me in the loop if they decide to sell each property separately, but at this time it will remain a package deal. I just don't see these as a package doing well for the seller in the market that I am in. I even mentioned to the seller that I would be willing to make an offer over his asking (after running the numbers). 

I'm new to real estate investing so this would be my first property if I was able to land this deal. Does anyone have insight into why the seller would benefit from posting this as a packaged deal? Since these properties bud-up against each other, and the parcel cut-out for the duplex runs into the parking lot for the commercial building, I was thinking this might be a deterrent from the seller listing separately. 

Any advice on persuading the seller to list these units separately would be greatly appreciated. I thought about covering the charge it would take to re-zone the duplex so that the commercial building would own all of the parking lot. Could the re-zoning of these two properties be a reason why the seller is trying to avoid that headache by listing as a package? 

Thanks!