Can't reduce it down to just one pin, but for me it was the very first container load of pins I imported back a few years ago. I had been through the process before with luxury vehicles but used pinball machines comes with its own unique set of complexities.

Lot of paperwork involved and even more sweating it out waiting for them to arrive and to ensure they were in the condition they were advertised (thankfully they mostly were).

Why? It was great to find an alternative to some of the overpriced dealers we have here in Australia and it gave a great insight into the profit margins that are involved with said dealers considering what I typically concluded firsthand as being superficial labour (e.g. wiping off the easy to reach places on a playfield without actually removing any topside components and then advertising it as shopped).

Have boosted my collection exponentially with subsequent container imports and even single machines to avoid domestic NIB price gouging, now I just need to allocate more time to get them all up to my own exacting standards.