If you turn the key and hear a single click, chances are good your starter contacts are worn. Depending on how mechanically inclined you are will determine your course of action. You can get a set of contacts from someplace like
www.startercontacts.com, or a local auto electric shop and replace them yourself. Or remove the start and take it to a shop. If you take the car to the shop, they'd just install a new starter and not deal w/ the contacts. I've replaced contacts on 3 Toyotas over the years. In my experience they seem to go ~120K miles