I don't know what else is in your market, but if this came up in mine, I wouldn't go after it. You need to plan for the 8% vacancy. That only gives you $100/month cash flow. This does not pay you at all for management. My personal goal is to get $200 door cash-flow for self managing... and yes, this is hard to find. That being said, here are some more thoughts...
1st... how solid is this loan quote? I haven't been able to get that high of an LTV without owner occupying. If you have a commitment letter for this loan, that changes things a little bit. Yes, the cash-flow is way below what I would like, but to get into a duplex with that little down would be great... and your ROI would look better.
2nd... are these expenses numbers that you found yourself, and how solid are they? In my market, this is what I would do.... have tenants pay for trash (Alaska lets you do this in a duplex)... get better insurance (I'd get a policy for around $1200 here), and drop your maintenance budget a bit since a lot of the big ticket items have been done (but I do most of my own work). So, I don't mean to second guess you, but if this is the best deal in your market, and you can get that financing, these things might make your numbers a little better.
3rd... if you want this property, I think you have the right idea... I would have done 5k or 5% over asking, but I don't have a feel for how much competition you have. The only properties I've bought with multiple offers, I offered 3k over and 6k over. I picked the 3k just to get over the asking price, and 6k just in case someone else picked an even 5k.
I hope these thoughts help.