Max Keyboard doesn't even offer custom keyboards any more (according to email response a few weeks ago). The Nighthawk and Blackbird (non RGB) are discontinued. Why buy sample switches from a company that doesn't offer and products that use them?
You can get used samplers on /r/mechmarket and GH forums for much cheaper, with a wider variety of switches.
This is great for finding the perfect switch that comes on a typical preassembled board. For all those people saying "oh it doesn't have this switch or that switch"
Check out novelkeys.xyz
I bought one with 8 keys, this wasnt enough, so I bought a big one and I dont use them at all. Why?
IMHO the main problem is that having >50 keys to type on a specific support is totally different from having one key to test on another specific support (=sampler tester kit): not the same feeling, not the same "click", not the same sound. Maybe a big improvement could be to have one row of 4 same keys so you can test with 4 fingers and have a closer feeling of what you'll get on a real keyboard, but right now I just feel like Sampler Tester Kit are useless.