A service, from experience, seems to be around £200 even for watches worth a fraction of that price.
I have paid it and more for a beloved thirteen year old Zenith with a broken rotor bearing, it was carried out by Genesis and was worth every penny.
My son had one recently tended to for me in Poland....serviced, lightly restored with new calf strap...all for 50 Zloty, about £35, but I add this just for interest purposes.
I was quoted £200+ in the UK, not Genisis, for the same job.
The watch below was my fathers who died in 1971, bought I should guess in the 1960's...so it's at least 50 years old.
It has NEVER even had the back off, let alone a service, It's accuracy is marvellous for a watch of this age.
I did, for the purposes of this thread try to get the back off but it looks like a front-loader.
In my watch box there are a couple of 'old' watches, one a 38 year old Seiko that have never been touched and just seem to go on-and-on.
I'm sure we all have such watches in an old box or at the back of a drawer.ll
I rest my case, 'if it aint broke then don't fix it', especially on watches of no value.
50+ years old and NEVER touched.
PA150627-RS by
Dave in Wales, on Flickr