Living Air Purifier

I was looking for an air purifier and my parents had an air purifier of life for years and seems to work fairly well. Now there are less than 200 dollars on Ebay. I do not know if it was a scam or if there are better units on the market? I need to get something for my 2 years old soon. Thank you!

Life Alpine air purifier is excellent. There are other great brands too, I think, but it's the one I used. It is simply remove allergens and odors. It smells like fresh air, no smell.