The image above details all the tools that were used to build the OpenFluidWarmer proof-of-concept prototype. I already had all of these tools in my toolbox. But if someone was on a tight budget and didn't already have the tools, they could get all the tools they needed for less than $200. Perhaps more important than how much they cost to buy is how readily available these tools are. Chances are that if you own a toolbox, you have at least five or six of these tools already. In addition, their wide availability makes it easy for someone unfamiliar with how to use one of these tools to either look up how to use it online or find someone locally that is familiar with how to use it. 

Looking back now, I think there are opportunities to reduce the number and cost of tools required. It was convenient to use a electric drill and drill bits on some parts of the build, but I could just as well as bored holes in the insulation foam by plunging in a hot soldering iron tip or by rotating a screw driver. 

Getting rid of the electric drill and switching to a butane soldering iron would remove the requirement for access to a wall outlet.