The rule of thumb used to be that you should be able to get 1% of the purchase price in monthly rent in order to have some positive cash flow. Thus, a $300,000 should bring around $3,000 a month rent. But, in today's market it's hard anymore to get that kind of money, thus the rules on single family residential properties has somewhat fallen by the wayside.
In Florida, and I understand in many parts of California, we have a glut of homes available for rent, due to owners that have turned into landlords, because they can't sell their overpriced properties. With so much on the market, rents have been coming down recently. Owners are taking what they can get in rent. Many, many are even renting homes out at a deficit just to have some money coming in. Unfortunately, we are hearing stories of landlords that are collecting rent, only to pocket it, and not pass it along to their mortgage companies! Thus, tenants are being forced to move due to foreclosure, without much recourse.
Since real estate is local in nature, your question would be best answered by someone local to the area of the home that you are referring to. It depends on how many homes are available for rent in that area, the amenities of the home, the motivation of the owner. How desirable is the area? What is the market rental time for the area, now? What is the market currently like in that area? And where is it projected to be headed?
Typically, here in our area of Brevard County Florida, in my experience, tenants that can rent a house for $3000 a month, don't stay long. They don't have to. They usually can easily afford to buy a home of their own, and not pay someone else rent.
The vacancy rate question, would also best be answered by someone local to your area. Remember, typically, the higher the rent, the longer the vacancy rate. Less tenants are able to qualify to rent the property in question.
Best of everything to you,
Sandy Shores, Realtor
M & M Real Estate
Residential & Investment
Florida's Space Coast