Jacques Mattheij:

After a trip to lego land in Denmark I noticed how even adults buy lego in vast quantities, and at prices that were considerably higher than what you might expect for what is essentially bulk ABS. Even second hand lego isn’t cheap at all, it is sold by the part on specialized websites, and by the set, the kilo or the tub on ebay.

After doing some minimal research I noticed that sets do roughly 40 euros / Kg and that bulk lego is about 10, rare parts and lego technic go for 100’s of euros per kg. So, there exists a cottage industry of people that buy lego in bulk, buy new sets and then part this all out or sort it (manually) into more desirable and thus more valuable groupings.

I figured this would be a fun thing to get in on and to build an automated sorter. Not thinking too hard I put in some bids on large lots of lego on the local ebay subsidiary and went to bed. The next morning I woke up to a rather large number of emails congratulating me on having won almost every bid (lesson 1: if you win almost all bids you are bidding too high). This was both good and bad. It was bad because it was probably too expensive and it was also bad because it was rather more than I expected. It was good because this provided enough motivation to overcome my natural inertia to actually go and build something.