as you've duly noted, "Sometimes it's all about 
who has the money." and while this is universally 
true, I'd add, who you know and more importantly, 
if they are actually willing to "SELL". I know 
many dealers/collectors who have cels I'd buy in 
a heartbeat for up to a couple thousands, but 
would they sell them? No. So my attempts to be 
patient hoping they'd quit or possibly entertain 
offers, is realistically a futile endeavor.

I can understand how for many collectors, they've 
set a reasonable budget for themselves and that 
is admirable and prudent. I think part of the 
problem is supply, moreso than demand. Many old 
collectors have moved on, though not necessarily 
completely out of collecting on an active basis. 
And one of the most overlooked reason IMHO, is 
the market has just dried up and cels are 
consolidated, much like the way corporations 
routinely undergo mergers and acquisitions. 
Especially for older cels from Miyazaki's films, 
BGC OVA, GunBuster OVA, KOR TV/OVA/Movie 1, 
Lodoss OVA, Urusei Yatsura TV/OVA/Movies, Dangaio 
OVA, Tenchi OVA & Movie 1, just to name a few.

You asked, "When does a cel's price become too 
outrageous for you?"... for myself, when the 
price of a cel exceeds my full annual ROTH IRA 
contribution. That is the max I'd pay for ANY one 
cel. And IF I actually paid that much, the cel 
better be, the cel of all cels (in my minds eye) 
for that applicable series. 

You also asked, "If a series ever came to a point 
where it just blew you away, would you keep 
collecting it?"... if you are referring to 
blowing me away financially, then... no. I do 
enjoy cels and respect the creative talents that 
gave life to the medium; but IMHO there are other 
long-term goals, which I'd like to accomplish, 
than simply collecting paint on acetate 
(regardless of how insanely beautiful). I am 
skeptical believing a cel I considered a dream 
cel at age 22, will remain at the same level of 
importance when I have a become a parent, or when 
I begin to have health problems because I am 
entering my twilight years. But these are merely 
my priorities in life.