Picture this:
1) Gogeta cels start popping up... and since 
they're the first in so many years they go for a 
fortune. (already happening)
2) Since people realize they can get a lot of 
money for the cels they start to sell em. 
(already happening)
3) When there are a bunch of gogeta cels out the 
prices start dropping but the seller's still sell.
4) In a couple months the prices go down from 
$1000  to maybe around $400-$500.

Apparently you haven't been collecting long.  The 
so called 'caca' was actually valued back before 
dbz hit the US.  And the extrememly rare cels 
were IMPOSSIBLE to find no matter how hard you 
looked.  Sure the prices were dirt cheap compared 
to now, but the chances of even finding a gogeta 
cel was 1 in a million.

Can you truly tell me that you honestly think 
that dbz cels will just continue to raise in 
price or level off at such a high price?  We are 
at the peak of dbz popularity, t-shirts and 
stickers at every store.  I dont know if you 
noticed, but the popularity of a series DOES 
affect its cel cost and even the fabeled dbz has 
to die or atleast diminish in popularity some day.

I personally think that a lot of the recent 
collectors were attracted to the hobby by the 
flood of recent popularity and as the flood 
drains down, so does the interest in the recent 
fad of dbz cel collecting.  So people WILL be 
willing to let go of a cel for less than what 
they bought it for if they really dont like it 
anymore and need some money.  Its sort of like a 
mix between stocks and art.  amoung other 
reasons, I think the bulk of dbz cel collectors 
collect for price and others for the intangible 
(spelling?^^) value, your outlook and opinion 
really reflects which of these reasons you 
collect for.

My 2 cents.