That price is a steal for that bike. This and the equally-revered Trek 720 touring bikes from the eighties regularly sell for over $1000 on eBay. This assumes the frame is intact with no dents or damage. That Miyata and the Trek are the two finest touring bikes ever produced.

Keep in mind that while you're wondering about the number of gears, somebody else might be buying it. Snatch it if you can - it's a treasure.