Seller is slow to release docs or allow me to speak with the property manager

[Mike Sattem]

Hello everyone,

I currently own several properties and work as a Realtor full time, so I am pretty well versed in how income property transactions should occur, however I have run into a snag with the seller of an apartment complex I would like to purchase and would like some advice from some of the seasoned professionals out there. 

The property (18 unit complex) has been on the market for three weeks, and I have been working with the listing agent (father of the seller) to get their financial docs. I have already verified their utility costs, taxes, insurance, and have spent a decent amount of time at the property poking around and checking out the tenants. After three weeks of asking for docs I finally received the last three years of 8825's, but none of them match what the listing agent is telling me (red flag!). Additionally, the seller's agent is refusing to allow me to speak with property manager to get a rent roll, copies of leases, etc, until he receives an offer, as he is worried someone will spook the property manager and they will jump ship. I have worked with this property manager in the past, and they will definitely not release any information without the owners say so. 

So, I am at a dead end. Short of writing an offer writing with a due diligence period requiring this information, I have nothing really to base an offer on. Additionally, the listing agent is claiming an 8% cap rate for the price, but no matter what numbers I use (the ones from the 8825 come out $100K less in value or what he claims it makes which come out $35K higher in value) I still cannot figure out his price, which makes me believe he has no idea how to value this property. In short, how do I deal with a listing agent who has no idea what he is doing?

Any help on this would be greatly appreciated,