Buying a "twin" or "brother/sister" guitar of one that you already have?

Not unusual at all & congrats!

I got three SE245's & gave one to my brother. The remaining two have different pickups, hums & P-90s, but even while there were 2 humbucker SE245's here, one was in standard E tuning and the other with different strings in drop D. Just enough variety for the same model.

And all of the PRSi here are 24.5xx singlecuts.
If the 'brother/sister' guitar is something that's pulling you in some way, knock yourself out, ya know?

I've done it myself. But after getting it I spent months and months comparing the two guitars, and only kept one, thereby wasting both my time and money.

Hey, I'm not sayin' it wasn't fun! ;)
Had a pair of Silver Sky's and for a time I was thinking about a 3rd with a maple board , then I got a Fiore and an NF3 so no need anymore for a 3rd or second Silver Sky.
I think that one of most every style of PRS is where I seem to be these days
without pictures, I have a hard time believing this actually happened
I have 2 2010 maple neck triple soapbars that are even both blue with quilted tops. One is my number one gig guitar, and has the scars to prove it. #2 is dead mint and is around when #1 finally needs a fret job and a few other things. I cannot bear the thought of being without one to gig with. And they do sound different from each other.