Usually the consideration is the payment of money but it need not be; it can be anything of value including the promise not to do something, or to refrain from exercising some right.The payment does not need to be a fair payment.

Those items like kayak, paddle board, BBQ grill, lawn furniture, floor mounted pull up exercise bar, stationary bike...stuff like that which the tenants are free to take advantage of but it is not part of what the rent includes.I think hotels do that when they say they have "complimentary newspaper service, complimentary WIFI". 

Then, when it comes time to exercise your option to purchase, you'll be more favorable to the lender.

Have the buyer in place, increase the rent if market allows, then sell it when buyer exercises the option.

Seller agrees to sell it for 100K.Wholesaler finds a buyer willing to pay 110K.Wholesaler purchases the property for 100K and sells it to the buyer for 110K.Profit from the deal 10K.At no time in the exercise is the wholesaler representing anyone but themselves.

They had given you the option to borrow based on their available cash and your financials at the time and then they simply withdrew their option since you were not exercising it and their cash position changed.So, the answer was/is to borrow the full line of credit, before they withdrew the option (or cancelled it, to use your term).

The seller must sell if they buyer chooses to exercise the option.

You accept the price and agree to give them a downpayment, let's use 10% for this exercise, of $10,000 with the remaining $90,000 on a Promissory Note that is collateralized by a Deed of Trust on the subject property.

Can you think of any other options that we can exercise?

What I regret is not exercising the pro-tenant laws Massachusetts has in place, holding the landlord and property management liable of the commission fee they charged me since they did not do a proper inspection of the unit between tenants.