(Standard disclaimer: All opinions herein are 
based on personal experience, observations, and 
research ^^)

Firstly .. Most Tenchi fans will agree that ppl 
should be aware of a basic pricing differential 
between the series. OAV will always be more 
valued/expensive than Universe, with only TMiL 
(esp. Achika) coming in higher than some better 
OAV cels. Universe should be better quality/more 
expensive/valued (take your pick, these synonyms 
are all subjective ^^;;) than Shin Tenchi cels 
(which I personally believe should never EVER 
reach the upper double-digits). You should also 
be aware that all characters have varying demand 
levels and this is reflected in price. 

Also, *if you are new to Tenchi (or any series)* 
never EVER base pricing differentials on EBAY or 
any auction for that matter. They are usually 
ALWAYS inflated over accepted market value, and 
unfortunately as more people think eBay is the 
place to get "deals," the more dealer prices may 
(and *have*) inflate to match, which hurts the 
average collector in the long run... 

As for that particular cel ... It's from episode 9 
of the OAV; I don't see too many cels of Ayeka in 
that nice outfit, but it is definitely overpriced 
for that quality. ^^;