I have a 2016 or 2017 Trek FX2 (if critical I'll look up exact year). Ride it daily for shopping, going to the gym and such. Store it outside, unprotected from rain. Took it to the store I bought it at to have new pedals and break pads installed. Guy at the shop noticed that the headset was loose. After opening it up (lots of rust inside) he's basically saying it's toast and he wouldn't recommend repairing it. Why? Because combined with the other things that need to be done, the total bill will come to about half the price of a new bike. Better to go with a new bike because this old one will just cause exponentially increasing maintenance and replacement costs going forward. I don't know the first thing about any of this and there is also a language barrier. I speak the local language where I live reasonably well but for technical discussions like this one it leaves a lot to be desired. (Thus it's also possible that I might have misunderstood parts of what he told me.)
My question here is first whether this sounds plausible, or whether the guy is possibly trying to pull the wool over my eyes.
And secondly if it does sound plausible, is there a better option than simply going for a new bike? How about replacing the frame and headset with a new one?