You could ask the manufacturer about how many drives they will keep in reserve to service existing units (or how long they think they can continue to service current units). All responsible manufacturers do keep extensive reserves of items that will no longer be supplied by the parts manufacturer. You could also rely on the internet to find such drives; most of the older drives are still available as new items, although some have become pricey.
Luxman makes their own proprietary drives and have recently come out with a new SACD player. They appear to be committed to offering "vintage" types of gear, such as CD players and turntables. I recently spoke to a Luxman representative at a local store's open house featuring this brand, and he said that their SACD player is actually a hot item, even in the US (CD's remain popular in Asia) market. He claimed that they are keeping a very healthy inventory of their proprietary drives, even though they have, so far, only had to make five replacements worldwide.
Luxman makes their own proprietary drives and have recently come out with a new SACD player. They appear to be committed to offering "vintage" types of gear, such as CD players and turntables. I recently spoke to a Luxman representative at a local store's open house featuring this brand, and he said that their SACD player is actually a hot item, even in the US (CD's remain popular in Asia) market. He claimed that they are keeping a very healthy inventory of their proprietary drives, even though they have, so far, only had to make five replacements worldwide.