If you don't it will negative cash flow.Note that most investors ignore very important items like capital reserves, vacancy, repairs, etc. when they calculate "cash flow" on single-family investments.

It also means that while 3% of 1m is $30k a year, it isn't something I can touch, so to speak.

Ethically speaking, you must make the payments on time.

Speak with whomever is in charge of lending (usually a VP).Go meet your banker in your finest clothing (you're a business man, dress like one) and put together all your financial statements.

Financed 80%, before-tax cash flow will be negative.

Taking a negative cash flow now for a good sale later, does that make any sense?

Is he just speaking from his personal experience, or is this something I should consider?

So, maybe using the actual collected rent (to negate the higher vacancy) and keeping with 50% (to account for higher management, though I've heard of this as high as 30% for vacation rentals) expense ratio would get us into the right ballpark.So, can you manage to collect something like $4600/month?

Its a negative number, since it a payment out and it reduces the loan amount (i.e., the "present value".)Determining the loan from the payment is very similar.

Yes, you can buy cash in an entity, then sell the entity, and of course, you will owe taxes on the profit (speak to your accountant).I hope this clarifies your original question on this matter as you received some good advice and some incorrect/bad advice.