100,000 units sold, software royalty of $7.50 a unit -- I make that a little over $2M in today's money. Not bad for what seems to have been about two months work.
A little later, the LaserWriter printer became the first generally affordable laser printer. But it was affordable only if you were rich or had a business case for it. The sub-thousand dollar laser printer took quite a few more years.
It was probably easier to come by in 1987. Nowadays if you have a unique idea in computing, there’s 40 years’ worth of computing professionals around to step in and take the job.