Andy,
One's enough for me. I don't plan anytime in the near future to get another K31 and I basically collect the bayonets to go with my rifles.
If I ever get serious about it, I'll probably stick to one of each type, not individual makers.
I sat down two days ago and came up with a want list, not too many bayonets on it anymore, ten to be exact. GermanS98/05, Austrian S1895, Russian
1891, Turkish
1903, Swedish
M1914, Belgium
1916, Canadian
Ross, US M4 with leather grips, Finish 1927, and a Polish Wz22/29.
Probably can't afford the Finnishor Polish but the others on a good day and a good deal I could probably pick up. My rifle list is considerably longer unfortunately. I only have the Austrian Stutzen for the above 10. I have bayonets but no rifles for another 10. So my want list is currently 19 rifles and 10 bayonets. It will take me YEARS to complete that list.
I'm limiting myself to the major and some minor powers during WWI and WWII with the addition of two neutrals, Sweden and Switzerlandbecause their rifles are top notch.