I've done further research for you, and in Aust the L120 is being sold for between A$85 and A$300, so US$50 seems like a bargain. It costs about US$340 brand new, although long discontinued.
Ensure it all works and that it can focus all through the zoom range. Nothing worse than a blurry photo that can't be avoided.
Find out the size of the memory card it will take. I use a 32GB card which in sports mode, 7 frames per shot, gets about 1800 photos (but that's with a second battery). I now take photos in landscape mode, at a resolution of 1920x1080, and I get over 200 photos, many I delete.
If you do purchase it, practice, practice, practice. All it will take up is time. You can recharge the battery, you can reformat the card (after downloading the photos) so it's not as if you are using (wasting) film.
There's not much difference between the L120 and the P900 on the outside, it's all what you can't see. The most obvious difference is that the L120 has 21x zoom whereas the P900 has 83x zoom.