There are a couple small differences, like the finish on the Neptunium enclosure costing a little extra, plus Neptunium has more film caps than Finally, but the two main reasons for the higher price of Neptunium are 1) the R&D process for Neptunium was more expensive and more time consuming, so I have more design costs to recoup there than I do for Finally, and 2) frankly Finally should be more expensive, but I deliberately keep it priced as low as possible because I want it to be everywhere.
My goal with Finally is for it to easily be someone's first Sushi Box pedal. It's small, it sounds great, it fills a need that just about every bassist has, and it's inexpensive. Then once you get a taste for Sushi, you come back for seconds. It's not a loss leader because I still do make a profit on them, but Finally has the lowest profit margin of any of my pedals.
