What is the base price of the bundle?

The base price is mainly used for compensating extra costs for bundling, e.g. packaging. You may want to bump up the start price from $0. 

It's only used in percentage (PC) and fixed-amount off (FA) discounts. Here are the bundle price calculations, e.g.

1. PC - select any 3 items ($10, $20, $30) at 10% off with a base price of $5
   1. The bundle price = ($10 + $20 + $30 + $5) * (1 - 10%) = $65 * 0.9 = $58.5
   2. With no base price (base price is $0), the bundle price = ($10 + $20 + $30) * (1 - 10%) = $60 * 0.9 = $54
2. FA - Select any 3 items ($10, $20, $30) with $10 off with a base price of $3
   1. The bundle price = ($10 + $20 + $30 + $3) - $10 = $53
   2. With no base price (base price is $0), the bundle price = ($10 + $20 + $30) - $10 = $50

The base price is NOT RELATED to the displayed price shown on the collection.