Is it worth getting an 11 year old cartridge re-tipped?

Yes - 100% worth it. Just had my MC rebuild done by Peter Ledermann at Soundsmith; he has been doing it for 40+ yrs. You send it in - he does a complete microscopic eval before starting any rebuild. You can pick your Cantilever and Stylus shape - if in doubt, he is a great resource & guide.; he will discuss options with you. If the rebuild is not worth it, he will tell you and if it is a complicated rebuild with lots of damage, no charge if it fails. All rebuilds come with a one yr warrenty. His website is one of the more extensive knowlege bases for anything cartridges. 

https://sound-smith.com/services

@jmrrobbie1  

What's the turn around time now in your experience?

The question is whether the suspension can be rebuilt, if that is needed.  I suspect each "retipper" will have a different answer to that question. So, ask. But I do not think that age of 11 years alone means that the suspension absolutely has to be rebuilt.  I have a 17 year old Koetsu Urushi sounding better than ever after only a stylus replacement, done by Expert Stylus.  The qualifier is that my Urushi was never under heavy use due to the fact I have so many other cartridges and turntables.

slaw...

I sent mine in at the end of last year...Peter was in the process of relocating his shop to a new location. Once the cartridge arrived at the correct address (my bust), he did the eval the next day and called me that evening. My issue was major = In the process of moving my gear - the cartridge snagged on my son’s shirt sleeve. Peter's rebuild included the suspension, some fine tuning and a new cantilever & new stylus. Total time was 6 days, then shipped back in two days. On his website he notes his rebuild time from 8-12 weeks…. depends on how many are in front of you. I got lucky with the short turnaround time. For me - I went with Sounsmith as they have the one yr warrenty with all rebuilds & also if the rebuild failed = no charge.
His cartridge knowledge collected over 40+ yrs of doing rebuilds can be found here:
https://sound-smith.com/how

Steve at VAS in Cliffwood NJ will have that thing as good as new (sometimes better than new).   And if it’s something besides a worn tip, he’ll let you know that prior.