I had a super loose coax out on my Mme as well.
When I opened it up it seemed so easy to fix that I was considering doing it myself.
That kinda says alot since I learned to solder/desolder through the TS archive.
I was only gonna fix it because I was selling the Mme, but just sold it as was.
If you want to get it fixed anyway I'm sure it would only take them 15 min. or so (prolly a 1hr. charge) plus the less than $5 part.
IMO the AES is the way to go anyways especially since it locks in. I had a really nice cable from Ed at Kindkable that came with my Mme when I bought it outta the YS. His prices are very reasonable and the build was top notch, check out his site if ya haven't already-
kindkables.com Edit: Rereading your post it seems that may have considered having a local shop do it. I'd prolly just go that route it's just a couple desolders / solders.