Bus Pirate v4 is back in stock at Seeed Studio. The Bus Pirate is an open source hacker multi-tool that talks to electronic stuff. It’s got a bunch of features an intrepid hacker might need to prototype their next project.
v4 has some great new features, but if you want a tool that “just works” the v3 is still your best bet.
You can get a Bus Pirate v4 for $40, including worldwide shipping.