The Croce d'Aune group was a very good group, between Chorus and C-Record. It has a lot of similarities to C-Record and there is some parts interchangeability between them. It was sort of marketed as the poor man's C-Record and was a perfectly fine alternative to it. The reason it didn't last so long was probably that the market niche wasn't big enough, although that is just speculation on my part.
I'm not really up on prices for this group, but I do know if you are seeking to max your value out, ebay off the parts. I guarantee you will sell every last little clip and connector in the group. I did something like a couple of years ago when I bent the frame on my CdA Tommaso. The things that people really want out of that group are the pedals and brakes - they were both sorta unique. The CdA deltas were a lot different than the C-Record deltas and although desirable, they don't quite bring the prices that the C-Record versions due. If your pedals are in good shape, call me

.
Anyhow, if you are trying to baseline the prices, I'd say figure out what the C-Record parts would bring, knock off 10-20% to be conservative, and that's your number. Again, for some of the parts it takes a pretty trained eye to distinguish them and if I'm correct, sometimes CdA had parts from previous years C-Record.
Its nice stuff, I'd like to have a full CdA group, it would be just like old times. For a while, they had an unusual rear derailleur with an actuating rod, which is the variant I had.