I believe that the affordable housing program pegs all prices to the monthly payment. This means that HOA, Interest Rates and Housing Price are fairly meaningless on their own because if one lever goes up the other levers go down. For instance if inrerest rates jumped up before you closing the price of the unit would be reduces and you monthly payment would be unchanged.
Where does this work against you. If you are on the sales side and interest rates spike up then you stand to lose money at that point in time. I was ready to buy a unit in Carmel Valley when the seller insisted that I pay her realtor fees. This was a ridiculous request as I knew I was going to ahve to pay realator fees when I sell so in essence she was asking that I double pay.
What she did not realize at the time is that finding a qualified buyer was not that simple. I found her more than she found me because I was educated on these programs. Additionally interest rates were extremely low giving her a profit on her unit. She balked and interest rates went up about a point before she found another buyer. I am fairly certain she looked back and regrets not signing the papers that day and paying the sales commission.
I still believe that there is very little risk to these programs. If you can qualify I would not overthink it. It is a better deal than renting and while you technically can not use it as a rental property who is to know if a friend moves in. Possession is 9/10 the law.