I've been accumulating coloured & patterned socks over the years! Have 5 bamboo ones from Sockshop (via TK Maxx) & only now are *some* of them starting to develop tiny holes after 3-4 years. So pretty good wear, considering!
I've never used alpaca socks before - are they itchy? That's why I've only ventured into merino wool so far in clothing - can't stand itchiness!
(I'd say bamboo is between cotton & wool, a bit thicker than modal - they work fine for milder temps but sometimes I will have to 'double wrap' them (with a thicker sock on top) if temps dip below ~10C).