What kind of terms can I get on an 8 plex

[Rigo V.]

1 -What kind of terms can I expect to get on an 8-plex I am looking at? Financials below. Right side is today and left side is after I do a few changes to it.  Its listed at 499K (too expensive) and I dont plan  on paying that. 

2- The owner has also stated that he might be willing to hold a partial note but he has a mortgage of 350K. I can't figure out how I can make this deal work and how to calc any potential balloon payment.