Those products were very affordable. The S-300i/S-350a were 2500, the S-350av was 4500, and the big S-550i was 5000. These were amazing performance/dollar products at the time. The new Vanguard integrated and Cipher CD/SACD player are both much better, but at 4.5k/12k respectively the price is higher now too.
Many company's make some models outside of the US to keep the prices lower. Unrelated (sort of): I worked at a B&W dealer for 16 years, and when the 683 loudspeaker was released from their new, non-British factory I was surprised/disappointed, but then I listened to them. Not only were they 1500/pr but they sound much better than the outgoing, British, 604S3 ($1600/pr) that they replaced. So equating where an audio product is made with it's performance (or reliability) might not necessarily reflect reality.
That said, rest assured, ALL Krell is made in Connecticut now. The new Vanguard integrated, and the iBias family of amplifiers are the best sounding amps they've ever made. Give them a listen. :-)