Dusty Room & Questions on Air Purifiers

Hey everyone! I'm not sure if I should post on here regarding the situation I'm having, my room gets dusty quite often and I have to clean it atleast every week. It gets annoying with how dusty it gets and I wanted to know if air purifiers are worth it? This is for a small bedroom so I wouldn't know if I'd need multiple purifiers or just one? Also should it be placed somewhere certain in a room or can it be placed anywhere else? I had my eye's on a Levoit Air Purifier but wanted more information from people who have more experience in these type of things, thanks!