[Daz(DJLFlapper)]

There is no right or wrong time to sell a heli due to parts being hard to get, The reason I say that is it is generally down to your own determination/love to keep the heli,
I myself have been in a position to sell my Nexus and step up to a new heli for ages. But I have grown so fond of my heli that I don't ever want to sell it now. I would rather let it retire fully kitted and give it a run out a few times a month. Remembering to fly it gentally and not risk it to some flight damage due to me pushing it. I have modded my nexus so much that a lot of people don't believe it was ever capable of such stable flight. So for this heli I'd rather it stay whole and enjoy it that few times when I do fly it.

As for becoming an antique! If the heli you have is now old enough that parts are no longer being produced eg Nexus, Then a few months after is the best time to sell your's off. If you are going to sell it off there are 2 ways to do so.
1 sell it whole as either a flying heli or as spares or repair.
This way will get it sold and off your hands but not to its maximum value.

2 Break it down yourself and sell it as individual spare parts for the models other people have.
This will get you a greater return for your heli parts, However you may not get all of them sold unless you price them right. Maximising your return for investment elsewhere.

I have at current 5 heli's and don't wish to sell any of them. I have great memories with all of them. With small investment in shelves I can enjoy them for many many more years to come. Over the years I have seen when someone has brought out an oldairplane to fly it creates a lot of interest with the older flyers. The same happens with heli's that are long since past regular flight.

Anyway if your thinking of selling then good luck, I hope you get what you want.