Hello Zack,
25% seems a little low for Maintenance, Repairs etc, there are lots of threads on the site that reference the 50% rule. As in 50% of your rental income needs to be accounted for as expenses excluding the mortgage. This includes other items such as Management, vacancy etc.
Now you may not spend 50% every year, but in the years when you need to replace big ticket items or if a tenant causes damage, falls behind on rent and has to be evicted then some years this may exceed 50%. (Personal experience) Although I am not sure how big your home is so with rent that high your maintenance and repairs may not be that high so I would suggest breaking it down into individual line items rather than just 25%.
Are you planning on managing the property yourself? If so you can save the property management fee, but then can you make sure the property stays filled and handle any calls with the tenant, set up lease agreements etc, Also every month the property is empty that costs you 8.3%. Try and breakdown the costs as individual line items, because with 1 month vacancy and paying a property manager that could be nearly 20% of your 25% fee. Are the taxes and insurance numbers that you quotes on an investment property or a personal residence. In South Carolina the taxes can be triple for non owner occupant properties. $750 a month seems high for a $300k property, but I am unsure of what is normal in NY
Also are there any HOA fees.
Also if the property has been on the MLS for 180 days, I would assume that the property is overpriced for an investment property, although I am not familiar with your market. But questions I would look for answers on are;
Have they altered the price over those 6 months? If they have not already lowered it, then their are either stuck at the price as they are underwater or not willing to take less, or they may be willing to negotiate.
What have other comps sold for in the area? How does the price per sq ft compare. If you are working with a realtor then they should be able to provide this for you
You also say current rental income is $4100, so is there a tenant in place, or is that the average for the area. If it is an investment property, is it vacant, how long has it been vacant, if a tenant is in place and it is cashflowing then why does the investor want to sell? This could be a genuine reason, such as they need the equity for a larger deal, or they are relocating, or downsizing.
Just a few things to consider, after the relevant inspections, and research, then you can decide what a fair offer is for the property. Just because they are asking $375k, doesn't mean that is what you have to offer, especially if they have not reduced it in 180 days.
Again, I am not familiar with your area, but you make the money with the purchase price and not when you sell the home.
Good luck