Well guys we have been at it here for a while so being my primary job here is the sales board I will offer my 2 cents.
The market will decide not me not you not a sum of parts X labor, shipping etc. This being said if I saw an obvious rip off I would send a PM to seller or buyer but it would have to be cut and dry as I really have no idea what they paid for parts , some good deals some really bad perhaps who knows parts are funny like that. I would like to think our high end modders are our most experienced guys and would price fairly. Going around nit picking someone else’s sales thread/ watch is very bad form and as stated above very subjective due to the great variations we pay for parts. Now discussing a watch's parts as in movements, case (is it really one of those!) are fine leave price out of it. So be sure you know your shit 100% before you taint a thread, buying well send a PM and negotiate if you feel above what it's worth.
The OP who now as a headache (imagine how I feel on the sales board every day) raises some good points as do others and we are here to protect each other but the market goes up and down 6538s were rare as hens teeth at least decent ones till StoneP started making them then mine were all worth less as he put out many nice ones. This may change if stone decides he is not making those or changes his hobby of course then they go up. At other boards vintage Rolex do not sell like here in money terms or at all seen something sit at a fair price that would fly here , supply demand gents let it do its job. See an outright miss on the parts /build well be polite point it out (better be very damn sure) otherwise mind your own biz.