I really agree with this, given my own experiences, but I will say some of the best bread I ever had came from a chef who started his own at a wilderness camp. Anyone who came out to camp, he would share it, but unfortunately mine went bad after a while.
All other shipped starters are just a shortcut to going to a local baker and asking for a donation (I've done this dozens of times, all over the world; when I've wanted a fresh/homemade loaf), or just spending a week's time and ~350g of wasted flour developing your own.
Is there a bakery that sells? Boudin doesn’t as far as I know.
<https://www.kingarthurbaking.com/blog/2012/04/05/make-your-o...>
There's now quite a sourdough ... culture ... substantially invigorated after the Covid-19 pandemic (xkcd:2296), with books, podcasts, websites, vloggers, etc. I picked up much of my own baking knowledge through these (starting with a few YT videos, and progressing through my own experimentation and further research). I'm still going and just had a couple of slices of my latest batch with eggs.
Starters are startlingly resilient, though you can kill them off or spoil them, largely through heat or prolonged regret.
As any good sysadmin knows, good backups are essential. I'd restarted my batch from a pinch of dough that was proofing in the fridge after one inglorious encounter with a microwave and housemate. After that I dried and froze a batch (King Arthur covers this as well: <>), and a tablespoon of the frozen starter plus about a half-dozen feedings has it going strong again. (This differs from KA's recovery method, but worked.)
Drying another batch to freeze as we speak, can never be too sure ;-)
Using someone else's starter can help bootstrap the process, but your own environment's selective pressures and new sources of yeast, most of whice come from whole-meal flour, which is what you should use to start your own batch. Note that bleached white flour, whilst it can be used to bake or feed however much I'd advise against it, typically lacks any active yeast. I did do some baking with unbleached flour when that was all that could be obtained, and the results while poorer than with unbleached / whole-meal were still quite acceptable, just not my preference.