I would like to buy a generation 1 Toyota Prius and keep it for long as I can, What should I look out for when looking to buy one, please help me guys
This is a difficult situation- you can't get replacement batteries for those first ones. You can use pieces from newer batteries to replace cells in the old one but even that might not be available forever. Apart from that, use the same guidelines that would help you find any other classic car: search in an area known for dry climate and get one with no rust.
if you are the kind of diy'er who can keep things going forever, and parts are readily available, i would look for one with as little rust as possible. everything else is more easily repairable by an experienced technician
Nothing lasts forever. New HV batteries are sold by Toyota thru their dealer network Prices may vary and installation by a dealer provides a warranty (3 yrs?) For eastern Europe, your battery might not be available, but probably would be in Austria, Germany, and most likely the Netherlands. If you're buying one for collecting, find one that is in great condition and if you repaint it, don't change the color. If you can, buy a good parts car as well. The best ones in the US are likely to come from the desert southwest. Rust and corrosion aren't an enemy here, and with used parts sometimes available, cheap, they are inexpensive to keep going.
Believe me, I'd love to go back and edit or remove my post. Unfortunately this board doesn't allow it, so now we have to trust future readers to read further along.