I'm surprised nobody has replied to your post, Terry.
I totally agree.
There is a lot of very poor weathering appearing on eBay items, mainly from two sources:
1. Buy a new item, spray a bit of brown round the bottom and list it for three times the prices, claiming to be 'professionally weathered'
2. Buy a job lot of ex-Lima/Hornby stuff from the 1980's and 1990's, give it a heavy coat of brown stuff and whack it on eBay
Most of it is poor, in terms of the fact that the person who did it clearly has never seen a real-life item (or even a photograph) to work from.
But, what really frustrates me is how they weather the front of engines. Like this Brighton Belle unit, they have merely sprayed a bit of brake dust etc. round the front, like what appears across the side of the body of engines. Errrmmm....really? Have you ever seen an engine with a thin coat of brown along the bottom of its front? It reminds me of the Heljan class 47, number 47555, which came factory weathered and had just the most ridiculous amount of brown dirt simply sprayed around the bottom half inch of the loco. Search it online....it is terrible!
Anyhow, yes I agree, but that's what makes the "eBay madness" topic so compelling to read...
Mike
P.S. The TTA tanks from TMC are really good actually....just wish they sold them in batches of 10, 15 or 20, instead of 4 or 5 at a time. If they did, think I would be tempted....