I completely agree with @DGErwin11 's very sound advice. It's not necessary to have a whole bunch of pipes, especially as a newer pipe smoker, to enjoy this wonderful pastime of ours.
Unfortunately, for me, I have never been one to follow sound advice, and thus, I have over 200+ pipes.
That being said, I consider myself to be more of a pipe smoker/pipe collector ( "PS/PC" ? --did I just come up with a new abbreviation??), so, having a lot of pipes (as well as restoring them/trading/selling), brings me another kind of joy that is often a nice complement to smoking them.
I will say that throughout the time I've smoked and collected pipes, I usually smoke a "stable" of pipes at any one time (usually about a dozen or so), and there are a few pipes that I keep going back to. These are either cheap, older estates (mostly factory made), or handmade, artisan pipes, from pipe makers I consider friends (who do very good work).
So, if I had to whittle my collection down--please don't make me do that--I'd say I'd be more than happy, pipe smoking wise, with about a dozen or so pipes (a cob, included).
Actually, you need a rotaion for travel. And since you cannot control humidity or airflow for proper resting, you should always have at least twice as many pipes as you plan to use on any given journey.....