Well... I'm completely new to this, so please take what I say with a grain of salt. I do need practice, though.
Without counting your three months in the summer at substantially higher rent, paying $395,000 for it wouldn't even satisfy the 1% rule, would it? $3500/month. June-August, +$4,500/month. That would average out to $4,916/month, and a total of $55,500 in rental income for the year. Then....
Prop. Mgmt. could be between 10-15%, but we could say 12.5%. Equates to -$6,937/year, so we're down to $48,563.
Maintenance I tend to see estimated at $3,000/year, but. Saying it would be 7% of rent every month would take us to $4,129/year. $44,434.
As far as utilities I have no idea, really... I actually am not sure if there is typically the expectation that the tenants pay for their own utilities or not. I'll just leave this one alone.
As far as financing, I'm not sure how you plan to accomplish it. This would be where the bulk of your money would be going every month most likely? If say, you were doing 20% down on a 30 year loan at 5%, monthly mortgage should be around $1696/month. That doesn't include property taxes, mortgage insurance, and anything extra. That would take us down -$20,352, so to $24,082 (still speaking in terms of yearly profit).
Then again, you're considering a starting bid at $395,000, so you could have financial means way beyond my imagination.
My lack of including utilities leaves a big void, but like I said, it's something I don't even know how to estimate too well right now. To just take a shot in the dark, if utilities were $1,000/month, we would end up at $12,082, or a net positive of around $1,007 per month.
If I didn't feel that I'd estimated out-the-yin-yang already I would try to do COC ROI, Total ROI, and Cap Rate ROI.
Also, if it's an auction, you're going to be headed above your starting bid anyway.
How'd I do, everyone?