People used to collect stamps, now they collect figurines, for example. If it's a rare item (or if you're not knowledgeable about the subject), you'll end up paying a fortune for it.
As for art... I don't think it's the artistic value that determines the price. Modern items don't even come close to the price of older ones.
It's more likely just a specific person's desire to buy something they like.

В тихой однообразной жизни всегда так бывает: каждый отдельный день бесконечно долог, но месяцы и годы мчатся с непостижимой быстротой.
I wanted to offer you some flowers, but a crown would suit a princess like you much better
Смысл жизни в том, что жизнь на тебе не заканчивается