I built the Trafalgar Square set from (mostly) pieces I already owned. While browsing Rebrickable, I noticed that I had 57% of the pieces, and that only counts my recent purchases. So I pulled the pieces I had from my collection and scoured the directions to see where I might be able to use alternative colors. I ended up buying about $40 in pieces. It was a lot of fun to plan the build and try to find substitutions from my existing collection. submitted by /u/paleoclimate [link] ...