One of the most important jobs of a real estate professional is to insure the efficacy of a buyer, especially in a townhouse transaction. First and foremost: is a buyer who puts in an offer on a townhouse financially qualified to perform and how do you deal with the resistance to providing this proof? The answer is simple. Google them. If they're legitimate, you'll know. If you are researching and can't come up with anything solid, ask for proof of funds. If he/she can't provide this proof of funds in the form of a bank letter or accountants statements then move on. If a broker refuses to provide this information for fear of insulting their buyer, more than likely they don't have the funds.
I have been met with several bizarre instances over the last year or so, buyers going to extreme lengths to prove they're qualified; bringing in architects and contractors, hiring lawyers, only to wind up exhausting time and energy with nothing to back up their offers with. And in the absence of a board to review this information, as in a co-op transaction, it’s our job as brokers to protect our sellers. The take away is:
Be tactful in how you ask for information, if need be have the information go through the lawyers but in the end, you will save yourself and your seller a lot of pain and headache. Take it from me, one who has learned from example.