The Google Home Mini is both affordable and capable -- for $49 it can pull up loads of information, control your music and videos and manage a wide variety of smarthome devices. Its tiny speaker sounds better than expected, though you probably won't want to play music on it.
Extremely affordable; Does everything the bigger Google Home can do; Manages many popular smarthome devices; Speaker sounds pretty decent for its tiny size
Microphones aren't very good for voice calling; Doesn't have as much third-party support as Amazon's Alexa; Somehow still doesn't support professional Google accounts