You can download the spreadsheet from a few posts above and play with the numbers. It depends on what rate you can get on your mortgage, how much cash flow you want, and what your operating expenses will be. The best I come up with, given $2600 in total monthly rent and assuming you want something like $400/month cash flow ($100 per unit), and a 7% loan is a maximum purchase price of about $218,000. And that is with you risking that you will only have operating expenses of 40% given that your management cost that you stated is only 6% and also allowing that your capital improvements will be low since the place is brand new. But, if you keep the property for the long haul, you will likely end up seeing those capital improvement costs.
You would have to KEEP operating expenses down to 32% and break even (no cash flow) in order to pay for a purchase price of $332K.
This doesn't account for appreciation of course, but you can't always count on appreciation. You can play with the numbers and come up with different scenarios depending on what the terms of your loan would be and how much cash flow you actually want.
BTW, I uploaded a newer version of the spreadsheet since I just realized that I was calculating the monthly cash on cash return, not the annual. :-\ So the the roi looks a lot better now.