From: Richard Erlacher <edick(a)idcomm.com> 
  I could be mistaken about this, but IIRC, a risky bet,
but ... wasn't the 
ZX80 a
  <$50 proposition back in the '80's and the
'81 slightly less, on the 
order of
  $29.95? 
The ZX80 kits originally sold for 199 British Pounds in 1980 (about US$400
at that time).  The ZX81 was advertised in Scientific American in 1981 for
$99 (the assembled version was $149).  By '84 the ZX80s were pretty much
gone and the '81s were at the $29.95 level you mention.
Glen
0/0