Should I use an escalation clause?

[Justin Reid]

I put in an offer on a bank owned (US Bank)property today. The house has been listed for 200 days, and just over 2 weeks at its current price point. A few hours after my offer was submitted I get a call from my agent informing me that the listing agent has told her there are multiple offers and I should prepare a "final & best" In the current market with so many people laid off and scared and sales volume way down I find this to be HIGHLY suspicious and do not believe there are multiple offers. 

I am strongly leaning towards my final and best being exactly the same as my original offer with the addition of an escalation clause where escalation is dependent on verified offers. 

My question is this a good way to call their bluff or is there another option I am not aware of.