Owner-Finance w/ Interest Only Loan. Good idea? Bad Idea?

[Chris Mullenberg]

I found a seller willing to sell to me on owner-finance terms, and he only wants to talk about interest-only payments. My initial strategy was to find a tenant-buyer for a lease-option, as this property doesn't need enough rehab to be a good flip. I'm a newbie, and was figuring my monthly payments to seller would reduce the principal a bit until balloon payment. Any advice on doing interest-only with the seller on a 5-year balloon? Good idea or bad idea?