Assuming annual housing appreciation of 4%, the apartment will appreciate to $583k in 30 years. From the initial investment of $36k that’s about 9.8% annual return. At 7% annual housing appreciation, it’ll be 13% annual return.
Will it bother you or mess with your calculations much if for the first few years (or very likely more than that) you receive negative appreciation? Have you factored in the time when your property will be unrented as well as the anoyance of being a landlord (repairs etc…)?