Purchase price directly related to rent.

[William Mccurdy]

So I have been doing a lot of calculations and it seems to me that purchase price is proportionate to rent. In my area rent is controlled almost entirely by military BAH. It's a plus and a negative but it seems that rent in generally 650-900, property tax is generally around 1,200 per year, and insurance is roughly 80 a month. It seems that I can't refinance a home for more than 85,000 without it being negative cash flow or too low of an ROI. Without calculating depreciation and tax benefits at the end of the year, it seems there will always be a substantial amount of equity left in the home. Is this generally the same in every market? Rent in a way determines purchase price?