What tools can I use to get better prices on a large list of parts on Bricklink?
A new developer has updated Brickficiency to the new Bricklink API...

You can download it here: https://github.com/WindmillHelix/Brickficiency2/releases

I've tested it shortly, it seems to work as well as the old Brickficiency.
Haven't tested it well enough to check if it provides significant better options than Bricklinks own Easy Buy feature... 

Just like the old Brickficiency, it's infeasible to process significantly long Wanted Lists as it uses a brute force approach (simply trying all store combinations)...