What's the 911 on re-tips?

I think you meant "what's the four-one-one".....

Ha, HA... you're right.

It’s been so long since I used a regular phone I forgot. Is 411 still a thing?

Maybe I should have said..." Hey Siri"

You won't be able to buy a "world class" (read "very expensive") cartridge for pennies on the dollar.  You'll probably pay 60-70% of retail, unless the cartridge is very much a vintage model.  In which case, the condition of the suspension is a concern beyond the condition of the stylus and cantilever.  There is a reduced cost lunch but no free lunch.

Depends on how anal you want to be about the retip. For instance, most cartridge manufacturers want you to sent the cartridge to them for repair and they are expensive. But if you have someone else retip and try to sell the cartridge later, chances are resale value will drop.

Deals? I like listings with broken cantilevers or missing styli, and I have sent a few of these (including ones I broke myself) to Steve Leung of VAS Audio. Steve is an incredible EE with pinpoint expertise and materials for proper quality retips at reasonable prices. 

+1 for Steve Leung at VAS.  Sent my old Koetsu Black to him which he repaired and re-tipped.  Couple hundred bucks, not totally cheap but reasonable considering the skill of the micro surgery required.  It's sounding outstanding, perhaps as good as it's ever been, so very happy with the service.

Not sure what your price range is but I'd figure you'd be out at least a grand including re-tip for something of higher quality, so not chump change.  VAS also sells modified versions of the Denon 103 for great bang for buck.  But getting your hands on a broken Koetsu or Lyra or similar class I don't think is all that cheap.