The number of damaged sectors you have is enough for not turning the HD on anymore but for one reason, a full backup.
Nobody can tell you how the disk will be. If the bad sectors are growing the disk is going to die. If the number stabilizes it may possible that the disk will continue to work for years. Its also possible that the disk will be unaccessable within the next n-minutes. I have a 40gb which can't initialize any more, sounding like rapid tack tack tack with power on, died from one second to the other. Any statistical calculation is useless for determining _your_ hardware failure time - if it dies earlier it will be.
One thing is sure, your hardware _will_ fail some day. My 200MB (yes, not GB) died lately, a Conner
CP3294F, 683/16/38, i can't remember or find out the production date, must be around 1992. The disk ran 24/7 since the year 2000 and i think it served well. This was low density technology. My personal opinion is with more and more capacity the risk of a failure arises. Todays "lean" production hardware is calculated to survive the warranty time. People store hundreds of GB data on a single disk. What is this data? What is it worth? How many hours of work are in there? How many pictures you would like to see some day to remember the past? What is that worth to you?
If your two disks are the same, from the same vendor, with the same postage, they got similar handling. The usage of the disks may vary, but as written before nobody can tell you when it fails. If you got your new disk, i suggest to do a badblock analysis first. That may take several hours but it's worth it. I got 2 new disks with already detectable badblocks, which were replaced by warranty without further notice.