I know I'm one of the folks who subscribe to the minimum 2 razors and the reason is that "One is none, and two is one".
As pointed out earlier, it takes very little to put a razor out of service, a bad stropping, a light tap on the faucet in the sink or when putting it down... there are a myriad of reasons and when one of them happens, you can't shave with a straight until your get your straight razor repaired or honed, unless you have a second one.
There is no need for 2 new razors, or one for that matter.... vintage razors are just as good, if not better than some new razors. A couple of razors in good condition, shave ready, from the SRP classifieds should cost less than one new quality razor, and you will have an equally comfortable shave. A new razor is like a new car, it attracts err.... shall we call them "whoopsies"? My last new car was a magnet for dents in the parking lots, scratches... bird presents from heaven, you name it... Now it's 6+ years old and who cares! <grin>
So, I would much rather see someone starting out with a pair of vintage razors, so even if something goes badly, there's always that second razor to tie a gent over, until the first razor can be honed/repaired/replaced. Using only one razor and barring any mishaps, there's still the need for that second razor when you send the first one out for honing. Naturally, that is why I have about 30 razors, divided into a "Dull" pile and a "Sharp" pile! I like to save my razors up for honing so that I can make it worthwhile getting the hones, my bench and myself wet. I find I rarely get around to honing my razors when I want or need to, it's more of a whenever I can find the time.
One last advantage to the 2 razor deal is that you can keep that spare, sharp razor, at the ready so that if, by chance, you are not happy with the razor you are using, you can just grab the next one and keep on shaving. It's true that with experience, you won't often need that second razor, but I have been caught with a razor I was sure I'd honed to perfection, only to find myself reaching for the backup because it was harsh, or pulled, or [insert reason here]. Without that second blade, yer stuck.
Regards
Christian