Tuxedo buy/rent

I need a tux for an event. I could rent one or buy one since I may need a tux a few times over the next few years.

Where is the best place to rent one? Price does matter.

How about buying? A friend bought one several years ago for what we paid to rent so this is an option. I missed the formal season so there may not be sales now. Do some rental places sell slightly used ones?