Brand New Investor- Need Help looking at the numbers!

[Asha Holly]

We found a potential property and were hoping some of you season veterans could take a quick peek at it and let us know what you think about the breakdown of the numbers?

We want to go into contract tomorrow..

list price.is $309.000
we are putting 20% down at 4.375 interest.
realtor "says" we can get $900 for one unit & $1500 for second for a 1 bed garden & 1 bed plus den for 2nd floor.
i think thats a bit on the higher side of rent but b/c the property has been completely gutted and rehabbed by investors it is possible for this "hotter neighborhood"
if we estimated on lower end of rent bout $600 & $1400 we put the out door cash flow at $140 per door.
we are putting an offer in but not exactly sure what to go in with. thinking $285-290.000
if you could take a look i would greatly appreciate it as we really like this property & hope it looks good enough that the numbers make sense.
i plugged numbers into an investment property calculator & canshow a spreadsheet to look at if that would give you a better understanding.
would so appreciate any advice you have!!
thanks in advance!!