When my older son started Piano lessons 2.5 years ago we started with a keyboard. That was fine for the first 9-11 months. (It wasn’t a full size keyboard – that was the issue for us.)
When he showed some interest/talent (he’s not a prodigy but he’s good and he enjoys it)… we decided to buy a used piano.
We just scoured Craigslist and ended up buying a very nice upright from a person in Carmel Valley. $700, had recently been tuned, was in excellent condition. The previous owner had just upgraded to a grand piano… so this worked out for us. It was $125 to have it professionally moved.
Since then our younger son has started playing – so it gets lots of use.
We looked at new pianos but the prices were too high… We got a piano that sounds new, for 20% of the new price.