Vinyl records grading scale

Guys, thanks very much for your quick responses. John/Arahl thanks for the links to the grading scale. That is exactly what I was hoping to find so that I can have an Idea of what each grade should represent.
I am very aware of the necesarily subjective nature of this process and the fact that most gradings will be a bit overstated. I am sure I will develope a feel for them after a few purchases I just want to narrow down the learning curve in terms not getting to many really bad ones.
My main concern is really noise when playing them more than visual marks wich in many ocassions do not affect playback.
Yeah, I put on my analog rig a Loricraft since inception which I consider mandatory some kind of decent RCM.
Any other comments with respect to cutt-off point for records from your experiences; or any other savy advices?
Thanks...

I would say that ebay seller typically visual grade only and even then, its often in a pretty dim light. I would consider most records to be overgraded by one grade. VG+ really is VG, etc. and M- IS the lowest I would go. Most importantly, if you are paying a premium price, they should be play graded. Just my $0.02.

This is a very sticky and subjective issue. The most important thing, as Arahl indicates, is to know your seller. The good ones will honor your returns if the record is not up to grade. But, as Undertow, suggests, the difference between an excellent LP and a poor one may be a matter of your own cleaning.
There is no absolute answer to your question as it depends on what you are willing to pay etc. A VG+, pre digital, reissue LP for $20 may be a very good deal compared to spending $300 for a NM- version of the same record as an orignal issue,... or maybe not. It depends on what you want.
Welcome to the world of analog collecting. It requires a substantial investment of effort into understanding labels, quality of reissues, remasterings and searching for what you are interested in, otherwise I would recommend investing in digital.

by sticking with a more selective visual grade you reduce the risk of noise, though the risk is still there.

I agree that most record grading is spurious and has no correlation to the sound. Many records are M or near mint. The latter should mean pristine, perhaps played once and unmarked, they very seldom are. Visual grading is useless anyway, you need to play both sides and what commercial seller has time. I agree with Arahl, get to know sellers you can trust and stick with them.
A good vacume clean does make a big difference too.