I sold my Gino/CRProps [finished/painted by Dave G.] on ebay, shortly before the AA/SDS helmet became available. I ended up getting $950. The helmet went to a nice guy in Spain, who was thrilled to have such an incredibly rare [yes - I'm naive enough to believe that there are actually much less than 50 of these out there] and beautiful helmet. I remember, that a number of people back then seemed to sell off their Gino/CRProps helmets, to generate funds for the AA/SDS helmets - at least, that was my reasoning to sell my Gino helmet... which a couple of months later, I very much regretted. That helmet was pretty awesome and I wish, it was still in my collection... oh, well - water under the bridge.
Would one be able to still fetch anywhere close to $900+ for a CRProps helmet today? I would think, that depends on whether you manage to find the right buyer? Quite frankly - to this day, turns out that the Gino ST helmet still ranks as one of the best ST helmet out there... maybe THE best. If you find somebody who is able to recognize the fact, that the helmet is... well, the best [maybe at par w/ a newer/nice-pull TE]... I think, you should be able to get anywhere from $650-$750+... my best guess.
Hey, last time I checked w/ TE - he was asking $850+ for a fully finished, glossy styrene helmet - so, why would a Gino helmet go for less than that these days? [Also keep in mind that the Gino does not have any decals but is completely hand-painted, etc. - no other helmet out there is fully hand-painted... well, that meatsock-guy sold a few hand-painted ones... but... they were basically TE recasts - right?]
Over the years, I haven't seen very many CRProps/Gino helmets for sale... especially ones, that were trimmed/assembled and finished by Gino and not Dave G. The Gino finished helmets are nicer and there have to be just a handfull of them out there... I've never seen or held [a fully finished] one in person - but I've seen photographs that confirm this fact... I haven't seen any Gino/CRProps for sale on ebay for a long time either...
I would just keep the helmet - it's a good one - and who knows, when you'll come across a better one? Everybody should have a ST helmet in their collection... so, might as well keep what you have and count yourself lucky?