My take on this is to put the would-be warranty money away in a contingency account.
If the printer breaks, use the money to pay the repairman if you are in a bind, or just buy a new printer if time allows.
If it doesn't break, use the dough to buy a new printer after 2 years or when the end seems near.
Chances are nothing will break in two years even under heavy use. My last two printers, a 7800 and a 9880, have given me perfect service, except for an occasional (ahem) clog. I replaced each at 2 years. The 9880 was at the 12,000 square foot mark and probably would need some TLC pretty soon. So I took the money in the contingency account and bought an 8300 for about cost of the two year warranty I couldn't have renewed anyway! Gotta love those year-end sales, December is a good month on which to pin that two year cycle.
Of course, all this supposes things are going well enough that a contingency account is safe from month-end molestations and tax-time raids. But that's another story.