There is no more Ah My Goddess series in 
production. The OVAs finished a long time ago and 
(as far as I've heard) there is no talk of a TV 
series. It's possible that the cel you saw going 
for a lot of money was an OAV cel. I suspect that 
the majority of OVA cels will always go for more 
money than comparable movie cels.

As for it being available via fansub. . . Since 
the OVAs have done so well here - and there is 
little financial risk to domestically release a 
one-shot movie - I doubt fansubbers will have a 
chance to even start translating it before it is 
bought for domestic release. HOWEVER, if for some 
reason it is not bought for domestic release (but 
I doubt US companies will turn it up) I'm sure it 
will be fansubbed. . . . It will take a while 
though since fansubbers will wait for the LD to 
begin translating (assuming no lack of funds).

I would rather have a domestically released, well-
translated copy! ^_^

Many Sharp Smiles,
--Drac