The XA series cameras are ancient, and if they have not had a service, however minor/major, they are going to fail at some stage during their life, and they have had a very, very long life. Not all of them are a risk; those in mint, well looked-after condition should give a few years of service, but they will not tolerate rough treatment or amateurs opening them up to fiddle with the electronics (unfortunately this is a very common problem with used cameras).
The electronic shutter is a common area of failure for all XA series cameras, particularly loss of function of the shutter button. No new parts are available, so repairs as needed introduce redundancy and further risk of unreliability, when and where such repairs can be made. I have owned 5 XA cameras over a 35 year period, and only one of those developed the dreaded shutter button/failure to fire malaise. It was not repaired but sold off for parts-only. The present XA was bought in 2005 and still working fine — touch wood.
PS: I would advise steering clear of Amazon and seeking out a tried and tested used XA series camera from a street store. There will always, always be risk ordering and paying for something you have not had a chance to put in your hands and examine. Same comments go for others of Amazon's ilk: B&H, KEH...