@Tristian Cavalli I know the property you're talking about, I own/live-in a duplex just a couple down from that one. It's well maintained, at least from the outside, and depending on the price could be a good investment. A couple of things to consider:
1) I wouldn't bother trying to contact the owners to get ahead in buying this, it's already been on Zillow for days and I'm sure they are getting numerous contacts already. I highly doubt (this is my opinion) they will bother to sell before it goes on the market unless you offer over ask. Also be prepared for there to be several offers on the table, when I purchased my duplex in that neighborhood I got it by finding an off market-deal. Before that 3 other duplexes in the same neighborhood had gone up for sale and all had multiple offers on them.
2) based on the listing the owners want to continue to live there for 3 years @ $1200/month, which is fine enough (though you might want to see about building in a rent increase every year), however the other side is also rented. Depending on how long is left in the contract, you may not be able to owner-occupy the property. I'm not sure if that affects your loan @ 2.75% down or not, but something to consider.
3) you listed the P&I @ $1,062, however that's approximately an interest rate of 3.45%, I'm not sure rates are that low currently (I haven't really priced them, but I'd be budgeting for more like 3.75-4%)
4) Vacancy should be around 8% as this gives you approximately 1 month saved per year (1/12 = 8.333%), CapX should be at 10% considering the age of the property, Insurance should be more like 8-9% (believe me, I priced insurance on duplexes like crazy and the best I could find was from State Farm and was around 8-9%, if you find cheaper let me know lol)
5) I'm not familiar with Native American loans, but do they come with PMI? Just want to make sure you consider that
Good luck, and let me know if you have any questions about the neighborhood!