When the time comes to exercise the option, if the property has appreciated more than you projected, they are getting a good deal.

I'm going to exercise my business plan according to contracts, approved by my attorney.  

Maybe your competitors are doing a better job at communicating what makes them different and better.You said you’re working with partners – have them do a mental exercise where they put themselves in the position of a prospective tenant and another exercise as a current tenant.

Let me make propose the next exercise to all.What is in general your MINIMUM Rate of Return for your Real Estate projects? 

@James Taylor,My initial example was a pure exercise in what's possible based on what some people I know did in the past.

If they purchase, the option fee amount paid will be reduced from the purchase price to lower the purchase price on the sales agreement, after they exercise their option to purchase.* The property is not sold and title is not transferred until the tenant exercises the option to buy. 

GOOD FOR YOU in exercising patience. 

If I want to exercise my contingency to cancel the sale and purchase agreement with the Seller.

That tells me that the bank may have claim to full ownership but hasn't exercised it's claim(So it would not work for her to try to sell me the property without the bank's involvement prior to closing). 

@Teddy Johnson, you're certainly right to resist this arrogant exercise of power.