I'll provide some perspective from the buyer's side:
Sure piecing together the earlier G1s or more popular characters are easy (Optimus, Datsum bros, Dinobots, 86 movie cast, etc.) but as you proved in your own situation, things are a total pain when you get to the "Master"-era. Are you willing to spend
this much on just Lube (hehe "Lube")?
And because I already owned their bodies from childhood, I really had no choice but to hunt down all the parts for the Autobot Headmaster Jrs (Nightbeat/Hosehead/Siren) and let me tell you, it took me YEARS of active scouring before I finally tracked down those stupid little head guns. I probably saw more listings during that time for complete figs than for those guns. Given to option to piece together those guys from scratch OR pay a bit more and buy complete, I probably would've chosen the latter.
Re: etiquette, I think things work out for the better when EVERYBODY abides by the "don't be a dick" rule. While not me selling directly, I've def witnessed my share of buyers actin' a fool. And sellers: if you don't list prices
you will get lowballers/what you perceive to be lowballers, it's the law of the land (again not my direct situation but I've seen it firsthand).
