eBay seller 5670violet has quite a few 2 Pound part lots of BIONICLE parts for $25.00 USD each. The shipping is a bit high at 15 bucks, but still averages 20 bucks a pound. This is less than what I usually see a single pound average for. You can probably save even more by purchasing multiple lots to get combined shipping.

It appears the seller has photographed each lot of parts individually too. I would still message the seller on this just to be safe, but you might be able to search for lot or two with specific parts of interest.