While quite common in their day, these Lionel standard gauge locos
were hard to find this time around.
Standard gauge is no longer the standard
When the TCA was founded, the members were mostly interested in toy trains from 1900-1920. At that time, a "standard gauge" was developed. The trains were big -- standard gauge track is about 2-1/8" wide from outside rail to outside rail. By contrast, in HO gauge the rails are about 0.64 of an inch apart. Standard gauge lasted through 1929, and for a long time standard gauge trains were highly desirable.
Over time, the demand has remained high for the few top of the line examples (mostly from 1928-1929), while slowly declining for the rest. This time around we saw only two examples of those highly desirable pieces, and a dearth of other standard gauge. But then, the demographic that most wanted those pieces has passed on. I never grew up in this era, but I think they are the coolest.