Typically you only go with a shaper for 1 of two reasons.
1. If you need to spin bigger bits then you can do safely in a router.
2. This is a production machine that will be running for hours a day,
Otherwise, a router is probably a more cost effective solution.
Or in other words, I would say it is the very rare hobbiest that would
need a shaper and only some production shops use them. Basicially, if
you are a cabinet shaop and making your own doors, you might want a 3