The latest cost workup puts the OpenFluidWarmer Gen 2 design just under $110; roughly $10 above the $100 cost target. It is important to note that these costs include shipping and are based on shipping to the United States. In the table above, items are listed from top to bottom in decreasing contribution to the total cost of the device. The sous vide cooker, electronics enclosure, and stainless steel mixing bowl being the top three most expensive components and representing over 70% of the total cost.

During requirement development I had little visibility on all the required safety features and how much each would cost. At the time, the $100 cost target was my best guess at a competitive upper limit. Since performing the hazard analysis, I have more insight into which safety features are important and which cost increases are well justified for risk mitigation. 

I am proposing that the new competitive cost target be moved to $125. This new cost target considers safety features that have not yet been added and an approximation of the price fluctuations that I have observed on the components over the last few months. Even at $125, the OpenFluidWarmer device is at most 22% the cost of a commercially available IV fluid warmer with comparable safety and performance.

I predict that an additional $5-6 of savings is possible with more creative ways of repurposing other common-off-the-shelf items. These savings are just difficult to arrive at quickly. I most often find these opportunities for savings when looking for parts online for other projects. It is always surprising to me how many specialized items that I am totally unfamiliar with can be considered commonly available. Browse AliExpress for ten minutes and you will get an idea of what I am talking about.