'People like me' - have records of 0-scams to date,
for reasons mentioned. There is a lot of inferential information within the 'feedback' comments (which also have pointers) and there are other ways of dealing with any suspicious aspects.
What you are generalizing doesn't quite compute: there is only One person per account per 'feedback rating'; spend x-years building up "no negatives" and spend it all in an orgy of not-shipping ?? [you might get to 3 or 4 before someone blew whistle to eBay]. BTW - there is 'insurance' IIRC for up to $250, from eBay for any such event. You can bet that after paying that - they will do some tracking down. Bad for bizness otherwise, even if it costs them $1K to nail one.
Nope, dunno what you're talking about. I'm sure there are the occasional short-lived scams; also sure enough that however vigilant, you cannot remove all risk. I'll settle for 100% no-scam thus far, over ~4 yrs.
(I also believe that 'test equipment' is a category which is least likely to produce either the gullibility or the cupidity it takes, to get burned via unrealistic expectations. Fuzzy bears and collectible bird shit might give other results. So YMMV)
Ashton