Last modified July 16, 2017 by Nathan

Buying LEGO Parts - Multi-Buy

The more LEGO parts you need to buy, the harder it is to find them all at the one store. The Rebrickable Multi-Buy feature lets you search through multiple LEGO stores, and prepare your shopping carts on many stores at the same time.

Click the Multi-Buy button on any normal Buy Parts tab.

Buy Parts tab

Step 1 - Set your store filters

Click the Search Stores button which will search for the best matching stores based on your filter criteria and the parts being purchased.

The resulting page will show a (potentially very large) table with all the parts you are searching for, and a list of stores that sell those parts.

Each cell in the table can be clicked to allocate a part (row) to a store (column). When all parts have been allocated to stores, the summary box in the bottom right corner will turn green to indicate you are ready to place your orders.

You might notice the initial allocation of parts to stores is not very smart, and can results in an expensive Total Cost.

Step 2 - Pick an algorithm

The default algorithm just picks the parts from the cheapest stores. The problem with this is that it results in a lot of stores.

The three basic algorithms

You can tweak the average Delivery Cost per store and see it's impact on the Total Cost.

  1. Cheapest Stores - for each part, pick the cheapest store(s) until the required quantity is fulfilled.
  2. Largest Stores - try to allocate parts to the stores that can satisfy most of the other parts as well. This has the benefit of minimising the number of stores being ordered from, and reduces delivery costs.
  3. Minimise Delivery - a much slower algorithm that iteratively moves part allocations around to find the optimal combination of cheapest parts and fewest stores.

Step 3 - Customise store selections

Once you have an initial agorithm that gets you a decent result, you can fine tune the part allocations by clicking the cells in the table. There are a few buttons to help manage large tables:

Helpful buttons

Step 4 - Buy from Stores

Once you have allocated parts to the stores you like, click the Add to Cart button for EACH store. Ensure each store has successfully added the parts to their shopping cart.