Musical instruments: guitars, pianos, synthesizers

Neck straightness (sight along it from the headstock), string height at the 12th fret, a working truss rod, cracks near the neck joint. On electrics — every switch position and crackle-free pots.

Digital: no tuning (acoustic needs it twice a year), headphone practice, and it moves without a piano crew. Hammer action is non-negotiable — a synth-style keyboard won't build technique.

Firmware version, what's included (power supply, pedal, cables) and compatibility with your setup. On keys, test every single key and control — sticking is audible immediately.

Used either way — the same money buys a class higher. Acoustic is simpler to start (nothing needed beyond the guitar); electric is easier on the fingers but needs an amp. A healthy used starting budget is 3–6 thousand hryvnias for an instrument you can actually learn on without fighting it.

88 keys with hammer action — non-negotiable — a sustain pedal, and 64-voice polyphony or more. Mid-line Roland, Yamaha and Casio second-hand run 15–30 thousand hryvnias and fully cover 5–7 years of study. A synth-action keyboard ruins hand technique — schools won't accept it.

Modern means predictability: consistent quality, guaranteed condition, service. Vintage means character and investment potential — with risks: hidden repairs, tired wood, expensive original parts. Vintage without playing it live and without a tech's opinion is a purchase for the experienced.