The deals I've stumbled upon

 Every afol knows that feeling when you see clearance lego.  You double check your eyes, you think how can I pay for this without debt.

As in the book "oh the places you'll go" by Dr. Suess...(my version)

"Congratulations, today is your day

Legos are on clearance today

you have boxes in your hands and walk quickly in your shoes

You can pick whichever self checkout you use" (and then argue with the cashier when it comes up regular Price

Reference pages 1-2 for "Oh the places you'll go" by Dr. Suess 

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In the case of used lego, you get so excited you forget 50% are tyco or mega blocks but you look past thinking well 50% lego is ok.  It's so bad, you justify buying even 5% lego.  Thrift stores sell ziploc bags that have about 20 lego pieces interspersed with weird plastic toy pieces or barbie accessories but you don't care how weird it looks because there is one of your favorite piece in there....

Well these are the sets that gave me a natural high when I saw it...

Initially I started collecting legos in 2000ish with a flea market find.  Then in 2003 I really got hooked again.  Here's some of my greatest deals:  pics below show multiple sets I bought in a single lot for $400

All of the above for $400!