Redwolf is correct. Cels are not going anywhere. In fact, that's part of the beauty of this hobby. You can afford to wait till you're older, with a stable career and then indulge in this hobby when it doesn't take such a toll on you. There's no need to rush.
One of my reasons for continuing to collect was that I thought these series would be extinct if I started collecting later in life.
I'd find it amusing how a cel I bought in the US in 2000, which I sold a year later, ended up on Japanese auction in 2002, and then next year in Takamura store, and then into Matt's collection
A DBZ cel I sold to someone in Germany turned up on anime-taro a year later, and then two years later on Japanese auction, then in two rubberslug galleries.