Obtaining financing for investment properties

My current debt-income ratio is currently @ 64%, but that should dwindle a bit once I pay off my one credit card. This also includes a refinance of my very first investment property that is currently being rented. I always wondered how the big time investors are able to afford 10 or 20 rental units. Assuming not all of them are own outright, I always wondered how one could obtain a mortgage for more than 2 houses!

I spoke with a friend of mine who happens to be a mortgage broker. He stated that if you have proof that they’re being rented and you have a rental agreement, then a lender would typically ignore that loan and now your debt-income ratio would be considered a little lower. Is this correct? It would still factor into their consideration in giving me another mortgage, but if the rent covers the mortgage and then some, then why should it be a problem?

The problem with me is, I know of two rental properties that I really want to obtain. Rent covers the mortgage and then some more, but will a lender lend me money knowing how high my debt-income ratio is. Also, how much would I normally have to put down on these investment properties? My first investment property was puirchased through an REO and I rehabbed it. it’s now worth $75k and I picked it up for $25k with $17k worth of work.