I wouldn't base it on time or even number of cels,
but rather knowledge. ^_^ But it's easier for me 
to define what isn't a newbie. Someone *isn't* a 
real "newbie" if they know how cels are produced, 
and important terms associated with it. Knowing 
how to shop for cels shrewdly and knowing the 
market a bit of what they're interested in (i.e. 
knowing how much is too much ^_^'') does not make
a newbie. Someone who goes only to eBay for cels 
will *always* be a newbie in my mind, even if 
for over a year... (And certainly ppl can be 
seasoned collectors and have only a dozen cels - 
maybe extremely good Lodoss OAV or Ghibli, for 
instance.)