Upright pianos are the most common used instrument on the market, which means condition varies enormously between listings at similar prices.
Quick checklist
- Play every key across the full range - listen for buzzing, sticking, or notes that sound noticeably different from their neighbors.
- Check that both pedals respond smoothly and do something audible.
- Look inside (most uprights open from the top and bottom) for rust on strings, moth damage to the felt, or obvious water damage.
- Ask when it was last tuned, and how regularly - a piano tuned once every few years needs more work to bring back into stable pitch than one tuned annually.
- Check the serial number's age against how the seller describes the piano's history.
For anything beyond a low-stakes beginner instrument, a pre-purchase inspection by an independent piano technician is inexpensive relative to the cost of discovering a major problem after moving day.