What is the property actually worth today, based on real comparable evidence rather than a portal estimate? What does it produce after vacancy, taxes, insurance, maintenance, management and the repairs you've been postponing?
What is your CPA-confirmed adjusted basis? For a long-held property this is rarely the purchase price. Capital improvements increase it. Depreciation claimed or allowable reduces it. Prior deferred gain from an earlier exchange reduces it further.
What tax rates would actually apply to you in the year of sale — federal long-term capital gain treatment, unrecaptured Section 1250 treatment on depreciation, the Net Investment Income Tax if applicable, and your California marginal rate? California generally taxes capital gain as ordinary income at your marginal rate, so there's no single flat number to plug in.
How is title held, and does the ownership structure match what your exchange or estate plan requires? Preliminary title, trusts, LLCs, and multiple owners all need review before listing rather than during escrow.
Finally: what do you want this asset to accomplish in the next chapter? Income, simplicity, growth, diversification, or something easier for your family to inherit? The tax answer follows the goal, not the other way around.