Could you tell me what some of those applications would be that would require a 1X probe? Initially I plan to use the 2102A to better appreciate Arduino projects.
tggzzz has covered it; when you need to measure the lowest voltages. A x1 probe can measure voltages at 1/10 the level of a x10 probe. The downside of x1 is that it loads the circuit more, and it has a much reduced bandwidth, typically in the neighborhood of 5MHz or so, even on a nice 200 MHz scope. The bandwidth issue is why x10 should usually be the default unless you just can't turn up the vertical gain enough to see the signal well at x10.
If you want passive x1 probes, the Rigol RP2200 ones are available for around $33.00 apiece from multiple sources. There are other branded probes available, as well. If you already had fixed x10 probes, it's unlikely you'd need more than one switchable probe at a time (in fact it's not THAT likely you'd need one at all).
Personally, I've got switchable probes, and I'd prefer fixed x10 probes, to eliminate the point of failure. The switch introduces two possible points of failure: mechanical failure of the switch, and human failure to check and set the switch properly. So far, I've only experienced the latter...