Start with completed sales if you can match them closely, but tighten the neighbourhood boundaries first. Riyadh-wide villas in that price band may differ too much in location and condition for 111 days to mean much. I’d also separate listings that sold from those withdrawn or repeatedly...
A simple worksheet could make this consistent: current rent; realistic achieved rent rather than the highest listing; expected vacancy period; advertising and preparation costs; maintenance history; late or missed payments; and the probability that a new tenant will be equally dependable...
Budget timing is another reason to investigate now. A first-time buyer may face moving costs, the first mortgage payment, furniture and immediate repairs together. If the scope is affordable without eating into the emergency fund, it could help decide what furniture can wait. If it would leave...