I never thought I'd own more than one rifle of the same caliber, but there are three of them that I like enough to do just that:

.223 - Two AR15s, an XP100, and a CZ527 Varmint

.243 - A Remington 600 (my first centerfire) and a Ruger 1B

.30-06 - A Remington 700 BDL and a Remington M1903A3 (original)

And, it's probably not surprising that these three calibers see most of my range and field time (aside from 12 ga, of which I have three). Price has little to do with it. I reload and have piles of brass, but it never seems I can't find any of the three on the shelves of the dealers should I need more. The .223s are great target and varmint guns, the .243s great deer and "windy day" varmint guns, and the .30-06 (particularly the M700, the Springer isn't scoped) is my most-often go-to elk rifle.

Don't worry about what the rest of us think of your caliber choices. The only person you have to justify them to is YOU!