The name "Nivico" is a contracted form of "Nippon Victor Company", where "Nippon" means Japan. It was a domestic brand name (although some was exported, too) used by Japan Victor Company, which originally was a a Japanese subsidiary of the American Victor Talking Machine Company, makers of the original Victrola. Through a somewhat convoluted history of takeovers and name changes, basically the same company is now best known as JVC, which stands for "Japan Victor Company".
The Nivico turntables I've seen have ranged from highly decorative but mediocre-quality stuff --a bit like the earlier and better Crosley stuff, but with a very Japanese flavor to the designs-- to quite decent quality. Some of the silver-fronted Nivico receivers and amps are decent. Without knowing specifically what model you passed up on, I can't comment, but the odds lean towards it not being anything you should kick yourself about.
OF course, Japanese domestic-market-only stuff from the heyday of the late seventies and into the eighties was often the best in the world at that time, but most of the Nivicos date from an earlier period, when postwar Japan's economy was not so wealthy, and the domestic stuff was not particularly great. It's mostly mass-market stuff; think Sears Roebuck instead of Nieman Marcus. Usually things with the Victor label are a bit later, and much better than things with the Nivico label. That said, if you want something with a really funky retro/vintage look (again, think of Crosley at its very best) with a Japanese feel to it, you'll find it hard to beat the styling of some of the old Nivico stuff. But audiophile? Well, it isn't quite up to that standard; mostly I'd buy it just for decoration. And the more ordinary Nivico stuff? I'd pass on it, almost always.