If you want to build up a large "creative bin" without spending a fortune, look for second-hand lots: Buying individual LEGO® pieces - Help Topics
With Pick a Brick, you can search by color, category, keyword, piece name or number to find the bricks you want for your creation. best way to buy lego bricks
: The gold standard for enthusiasts. It is a massive marketplace of independent sellers where you can find almost every piece LEGO has ever made. You can upload "Wanted Lists" from sites like Rebrickable to find sellers who have most of the items you need in one go. If you want to build up a large