Yes, It's pretty cool when you come across a hoard of a certain card when going through bulk lots. And yes, as mentioned by another comment in this thread, player collectors (as well as speculators) will somtimes hoard a particular card. I've come across several, my top ones (that obviously didn't pan out)....
Rnk Series Card # Playa(s) Amount
------------------------------------------------------------
1... bb1989donruss...... 40... Ron_Jones_PHI............ 96*
2... bb1991upperdeck.... 17... Mark_Lewis_CLE........... 61
3... bb1991upperdeck.... 23... Andujar_Cedeno_HOU....... 56
4... bb1991score........ 388.. Adam_Hyzdu_DP_SFG........ 54
5... bb1991score........ 390.. Rondell_White_DP_EXP..... 53
6... bb1991score........ 676.. Aaron_Holbert_DP_STL..... 52
* I don't differentiate between the "INC. vs INC" or "dot, no dot" variations in the Donruss series.