Trelja, in 95% of the cases, when it comes to a well designed digital player that does not have faulty processors like the Philips SACD1000 for example, the laser pick-up is the only part that would fail. Whether it will start skipping or it would say "no disc" when you load a CD, it is still the laser.
When it comes to a regular CD player, it can work even 20+ years, especially when it comes to top-line CD players built around the flagship Philips and Sony (an couple of others) transports/laser pick up assemblies.
Unfortunately, this does not apply for the laser pick up designed to read CD and DVD/SACD. These latest technology devices are a lot more complicated than a usual CD laser. Also, the actual laser diodes in a CD/DVD laser are working much harder compared to CD only pick up.
Of course, it really depends on the usage. If you have CD/SACD player only, you may have it working for 5 years and more given you're not using it 24/7, and especially if you are playing CD's most of the time it will last longer. When it comes to universal players, and if you also watch DVD movies on them, the life expectancy is shorter. Depending on the quality of the laser, the life can be from few months to couple of years.
In 99% of the cases, replacement laser assemblies are available in the range of $90-200. It is fairly easy to replace them too.
Bottom line is, if you like the sound of a certain player you own and it stops reading the disc, there is nothing to worry about.
Regards,
Alex