The Biqu B1 isn't just great for the price; it's great, period. It prints reliably, and it's easy to operate. Although it needs some construction, the build guide is comprehensive and everything is well labeled, so any skill level should have no issues putting it together.
The BIQU BX was a reliable machine during my time with it and I can't really complain about its performance. BIQU managed to deliver a well-made printer for an affordable price (kickstarter price) and that's great! The retail price of ~550$ is a bit steep for my liking. You get all the BIGTREETECH hardware to play with out of the box, and with firmware upgrades you might get new features over time.