All good advice... I'd also suggest looking at the AT 4021s, 4041s and 4051s. I believe one of those AT series are switchable pattern, too, but as Burris points out, really, one set of excellent cards used by someone who knows what they're doing is the ticket most of the time (although I'd also put in that one pair of excellent hypers is also awfully handy if you record in places that are indoors and noisy).
It is worth noting that those AT mics cost more than those $500 Busmans, at least new.
Then why do I have 4 pairs? And why are you getting one more pair -- though conveniently dropping me to 3 pairs as it raises you to 2.
(Yours are on the way, BTW. I'll send tracking shortly.)
My over-abundance of hypers that I'm working to pare back notwithstanding, I actually agree with Burris about the cardioids. I've often owned cards only at several points in my taping career, and they are very versatile and you can make lots and lots of good tapes with just cards at your disposal.
I don't know that much about the Busmans' sound*, though I know a lot of people really like them. So I can't comment on them specifically. If they provide something in the same quality for the price as a single set of cardioids, obviously it can't hurt to have other patterns to play around with and try out given the right conditions.
But I would agree with Burris in that if you can get better sound for the price for a cards only set, I'd recommend that option. Even in cases where say you'd prefer using hypers, IME a good sounding set of cards will make better tapes than a mediocre set of hypers (not to say that the busmans are mediocre). As a for instance, I was convinced recently to run my milab cards for a Phish show in a ~6,000 person hockey-type arena (from pretty far back). Perfect place to use hypers, and I ran milab cards along with Gefell m210 hypers. I actually like the milab recording better, and Gefell m210's are pretty much the best hyper out there (again, IMNSHO).
I did actually "start" out with AT4041's (after upgrading from SoundPro micromics). I got mine from 8th Street, which I see still sells a stereo pair of AT4041's for $500, so they can be had new for the same ballpark as busmans. I'd certainly at least put them on the consideration list.
*note on my "experience" with the busmans: I've never owned or really listened that much to the Busman BSC1, but I did own for awhile a pair of busman-modded Avantone ck1's, which I'm led to believe are the same or very much like the BSC1's. I liked them for sure. To my ear better than the roughly similar (chinese) Studio Projects C4's and comparable to the ADK SC-T's.
To end this long ramble, in the way of Chinese mics, I've owned Studio Projects C4's, ADK SC-Ts, Busman modded Avantone CK1's, and now own Charter Oak m900's (similar to Pelusos I hear). While I like having multiple patterns to play around with, I liked the sound of AT4041's better than all of these. The usual caveat that ymmv and everyone's ears are different.