I had a similar situation when I picked up the Pioneer 510H DVD/HD recorder. However, the price for 2 additional years was $50 Canadian. That's even cheaper than a replacement 80GB drive and the reason was this recorder classified as DVD player
Anyway, the store I bought it has a policy that if you never use the extended warranty, when it's up you can redeem the $50 toward another purchase. This for sure will get you back to buy something else, but I guess it's fair for us whether to debate to get it or not.
I think the $200 is quite high though on the Sony recorder since it's going for less than $1000 Canadian and I'm sure $200 you're referring to US$?
Thanks,
Simon