I prefer to look at Gross Rent Multiplier (of 4-5) as a way to "sniff" the deal and then use a cap rate based before and after valuation of the property to assess its merits. 

In that case @Molefi Branson, you should vet multiple sponsors/operators that are best aligned with your goal to "conserve your seed money" and hopefully make it multiply too :)Pretty soon you'll be able to weed out the rookies from the veterans.  

Or...you could roll ALL the money you leave  with, multiply by 4, and go shopping for a lot more units and defer the gains for sometime in the future.  

The buyer pool multiplies this way.   

That is our 'multiplier number'.

Your market would be considered the Luxury Real Estate market and normally the revenue multipliers for seasonal vacation rentals here is 4 times annual rent rates - and so done correctly you would more than cover your holding costs :)As I said depending on where you buy you may encounter restrictions on the minimum lease period you can offer and so you need to be careful where you buy - unfortunately I hear it happen a lot that buyers end up buying a second home they can't make work because they walk into a min lease period their Realtor never told them about or didn't know to check on.Hope this helps.

However, if you want drill down further, then you have to determine the net operation income, and multiply that by a market cap rate to arrive at a value ballpark.

I know that the percentage will very by size and bedrooms, but it is definitely easier to work with numbers if you simplify it like that instead of trying to figure out how many average cleanings per month multiplied by the cost per a specific unit type.

These multipliers are just rules of thumb

City Sewer connection can be very extensive, compare to yearly cost, try multiplying for 10 years cost versus connecting (if available) to the city plus seweage charges.