If it is a very expensive piece of gear, I would consult with the manufacturer about availability of parts or whole assemblies. Most long term manufacturers will have an inventory, but even that may not last. If you are really committed to a particular model, you might even buy spare transport/laser parts.
I personally think that digital is fairly mature technology and some older models are quite competitive. A lot of older DAC chips are better than what is currently available. Manufacturers have to stop using these chips when they are no longer made unless they have purchased a huge inventory or are making a small number of elite products. For example, Zanden and Naim use legacy chips for this very reason -- better sound.
Almost all manufacturers have to go with whatever chips and transports that are currently on the market. The priority for the chip manufacturers is NOT high end audio. Each "improvement" in a chip, warranting a new model, is usually emphasizing smaller size and lower power consumption (for use in mobile devices).
I personally think that digital is fairly mature technology and some older models are quite competitive. A lot of older DAC chips are better than what is currently available. Manufacturers have to stop using these chips when they are no longer made unless they have purchased a huge inventory or are making a small number of elite products. For example, Zanden and Naim use legacy chips for this very reason -- better sound.
Almost all manufacturers have to go with whatever chips and transports that are currently on the market. The priority for the chip manufacturers is NOT high end audio. Each "improvement" in a chip, warranting a new model, is usually emphasizing smaller size and lower power consumption (for use in mobile devices).