I am in sales and I sell air purification, but it is expensive. I need advice on where to find prospects.?

I am not comfortable goig door to door but it is an option. I need to make sales ASAP. I need advice on how to advertise for cheap and find potential customers. I need to get people interested but they have to watch an hour and a half demo that is very educational. Anyone in sales have experience and advice on how to improve my sales?