What percentage of the 50% put aside for maintenance, management, taxes would be your max limit for the taxes?

I ask because I know taxes vary greatly all around the country. The area I am looking has, for example, a duplex at $169,900 one side rented for $775 and the other owner-occ. The taxes (researched through county website) are around $3400/year. I think the property is over-priced based on the numbers. But how about that percentage of 50% that is going towards taxes?

There is also a duplex at $121k both sides rented prob around $750/month each based on local numbers. Those taxes are also around $3100/year. I think these two properties have a high percentage going towards taxes, but wanted to check in here to see what others think about this.

There is also a property at $159,900 that has 4 units, prob $750 each based on local numbers that has taxes around $2200/year. Where do those taxes factor into my analysis and the 50% rule?