You would think that with the job I do I'd have had lots of different lenses, but I haven't.
I have only ever sold one lens, that was a Tamron 18-200mm f/3.5-6.3 XR Di II and that wasn't a straightforward sell, it was a swap for Canon 50mm f1.4 at Jessops. So apart from that one lens, I have all my others - the collection isn't that big.
Canon 50mm f1.4
Canon 24-70mm f4 L
Sigma 70-200mm f2.8
Canon 18-55mm f3.5
That's it! I figured that I should have two telephoto lenses and a portrait lens. But here's my logic;
I shoot weddings. I need the range. I have a full-frame AND a crop sensor on my waist all day. So my 50mm can become an 80mm, 24-70mm becomes a 40-110mm (ish) and my 200mm becomes a 320mm when I use them on my crop sensor.
Let's be clear though, I NEVER use my 70-200mm on my crop sensor for a wedding, most of the day is shot on my 50mm on my full-frame and the 24-70mm on my crop to give me that reach when I need to get into the audience during the ceremony for example.
I only really break out the 70-200mm for the speeches, portraits and any special shots we go off to do.