QUOTE(WCO @ Apr 28 2007, 12:11 PM) [snapback]319963[/snapback]
gxseries, I am not a collector, so I do not keep coins.

I sell them.
[...snip...]WCO
Теперь всё ясно -- it's no secret that slabbing is more seller-friendly than collector-friendly!

Although I, too, own a few slabbed coins, I buy them more for (self-)educational reasons regarding grading practices (but not for reasons of authenticity). Everything has advantages and disadvantages; the more of one, the more of the other.
I have a Yeoman blue book (for USA coins) published in 1966, well before NGC, PCGS and all the other such companies were even dreamt of. It is very educational reading material ... but it would be somewhat OT to expand on this subject in the Russian coins forum.