Why invest in expensive electrical air purifiers when you could purchase a few types of houseplants to clean and filter your air naturally and inexpensively?
Sensory Gardens: "Use plants that play on the senses, such as fuzzy lamb's-ear, textural succulents, or fragrant lavender." (though not many eat it, lamb's ear leaves are edible, and most fleshy succulents are edible)
Money does grow on trees...and on bushes and vines and groundcovers, too. With edible landscaping, saving money never looked and tasted so good! http://www.bhg.com/gardening/vegetable/vegetables/edible-landscaping/?socsrc=bhgpin042415ediblelandscapin