My 4900 is just under a year, and I recently bought the 2 year extended warranty. What made me decide was that I had bought an HP Z3100 24" printer with built in spectrophotometer. After the rebate it cost me about $3400, and I thought it was outrageous to spend what HP wanted for the extended warranty. About the middle of the 3rd year of happy printing, the drive belt self destructed. HP wanted more than $1200 to even look at the printer. I decided to replace the belt myself, and followed a video that detailed very step. However, when I got the printer back together I got some error messages on boot-up. I called HP and they refused to even send a person at any cost, since I had tried to fix it myself.
You can imagine what a 24" printer looks like, out at the curb waiting for the sanitation department.
After that, I decided that $535 was pretty decent, after all, for my 4900.