Money set aside for Investment STR - how to evaluate purchase

[Trent Reeve]

What is the general rule on buying investment STR property if you cant normally absorb the mortgage payment forever? I have enough set aside that i could go a little over a year with no rental income. But is it normal to be able to completely absorb the mortgage payment or do you go into it knowing you need that rental income, at least in the beginning? Changes the dynamics of what I properties i would look for.

for example, i can take on another mortgage payment of say $1k/month no problem with no change to day to day life. But if i look at a property whose total monthly payments is say $2400, but can rent out at double that or more, and I have cash on hand where no rental income for the 1st year isnt a problem. It could be viewed like a business, that I am betting on myself and the property for income, not unlike any normal business starting up. But is that the norm?