IS there allot more collectors who isnt on the forums.
It's actually a great score, if the title is going for anti*-grammar points... (Anti*, hence the positive score I'm getting ready to present)
IS is all capitalized. +1
IS instead of Aren't. +5 (Which is still a bad way to begin a sentence...)
allot instead of "a lot." +5
who instead of "that" or another word. +5
isnt without an apostrophe. +1
isnt instead of aren't. +5
. at end instead of "?" +10
Score:
32. Out of a 10-word sentence. Not too shabby at all. Not sure what the record is... Too many contestants in the world!
Not real sure on how to grade for the usage of "more," as it just makes the whole thing wonky...

If the sentence read, "Aren't there a lot more collectors that aren't on the forums?" that would read ok, and none of us would have Grammar Nazi'd up, but probably just "Aren't there more" would work better.
BTW, Kjeffrey, all this is all in fun, I hope you realize that. Lord knows I have written sentences in my life that would have made my 2nd grade English teacher squirm a bit...

And I've probably made a few errors in this post, I would imagine...
I actually enjoyed the subject line, and as M1A mentioned, thought of Post-It noting it myself...