9. Your Income
Your income is important whether you're renting next or buying next
If not planning on buying in cash for your next purchase & selling an owner occupied home, your income is typically going to be a significant factor regarding your next home, whether renting or purchasing. If your income will be substantially lower than when you purchased the property that you are planning on selling, it's important to have realistic expectations about what you can afford, also considering any down-payment that might be involved that could be more or less than your last purchase.
If selling an investment property, it's important to have a plan for how you will invest the proceeds of the sale if acquiring proceeds. If the property has a monthly negative cashflow, that's important to consider for your income as well.
Those of lower income in some cases would be better suited to rent out rooms than to sell. Some of median or even high income would prefer to do that just to be frugal or possibly to have more company.