Lowering rent for tenant to maintain status quo

[Justen Ashcraft]

Let me know if anyone else has done something similar. I have a property in a c class neighborhood, and I had increased the rent on this door to $850 a month last year. Found a reasonably good tenant with 2 children, and have had minimal hassle. Tenant informed me that they were looking for a single family house, my property is a triplex, and that she would most likely be moving at the end of the lease(1 year). I offered to take lower the rent to $800 per month, a $50 decrease, if she signed for another year. She agreed. I know I'm losing $600 for the year, but I'm also saving $800-$850 by not having a month of vacancy. I'm also saving whatever cost in paint/repairs. Is this a fiscally intelligent decision? Thanks in advance.