@thelastpsion as much of an amiga fan as we are, don't think it would fit "educational" and "under £100" (the best basics were third-party commercial, it was far from a beginner friendly computer compared to something with basic-on-powerup in our opinion)
are portables an option? the amstrad NC100 is a bit terrible, but it has a decent basic you can even make to play music over the built in speaker and often goes for quite cheap on ebay
@mavica_again You do make a good point. I don't mind it being a bit complicated (it's meant to be a challenge of sorts). The plan is to have a range of machines over the ages, showing the different experiences that people had.
I'm so embedded in the Psion world I hadn't thought of the NC range! I agree, I don't like them much, but the BBC BASIC is good, and you can get them to run CP/M.
@thelastpsion p.s. if you need a vintage computer repair person in the UK we are in Devon and have resuscitated many a micro