Voted "one and a spare" because I have two violin bows and two viola bows. Again, note that my viola is is my main instrument and I switched to it almost completely within 2 years after starting violin. My backup viola bow cost about as much as both of my violin bows combined.

Primary viola bow: C.F. Iesta hybrid bow, their top of the line. Cost me $520, compared favorably to wood bows I tested that were up to $2500. (When I went shopping for it, I expected to spend $1500-2000.)

Spare viola bow: $250 wood bow, basically an intermediate-level student bow. I actually prefer it for Baroque music because, if held above the frog, the weight distribution resembles a Baroque bow.

Violin bows: both student-level bows, one $150 and the other $100. The $100 bow was the first one I bought (was the cheapest in the shop I went to after I inherited my great-uncle's violin without a bow), and I upgraded to a slightly better bow a few years later when an orchestra I was playing in had too many violas and asked me to switch back to violin for a year.