What is the best air purifier for dust?
I moved to NYC and hate the dust. I’m an asthmatic and allergic to dust. My room is 12 x 15. Have tried Hamilton (hepa), researched on ozone purifiers (everybody, almost, says it’s bad), tried ionizers (did not work). What else is out there, AS PER OTHER"S EXPERIENCE, that won’t kill me with the price tag and replacement of whatever (e.g. filters). If somebody answers for me to move, it’s not an alternative as of this time. Please just help!!

If you have central A/C/heat then the 3M Allergy furnace filters are the way to go. Replace as needed (you might need to change more than once a month if there is a lot of dust). My allergist recommended them and they seem to help as long as I don’t open the windows and let new pollen in! Your other options are cleaning really well, using an "allergy" vacuum, allergy covers for mattress and pillow, no carpet if possible, keeping all "stuffies" in plastic containers, no curtains….your options are endless. Usually it takes a combination of different measures before you find any relief. If you have to clean for yourself (its better if someone can help with "dusty" tasks like vacuuming and dusting) get a good dust mask to wear and always dust with a wet cloth as dry or feather dusting only stir it up. Good luck and happy de-dusting!
First is to stick with a good hepa filter sized properly for your room. If you have it in a single room like your bedroom be sure to keep the doors shut. There are some filters that also employ a UV-C bulb that will kill off many airborne pathogens like fungi and virus particles. Check on EBAY they have many to choose from. But do not use ozone it is toxic to the lungs and will harm not help. Another source of dust can be carpet, if you vacuum you can be putting dust back into the air. The best vacuums are the water vacuums from Rainbow they are pricey but sometimes you can get them used. They last a lifetime.