When are you too old to be buying your first American Girl doll?

Even though I only owned Felicity's and Kirsten's stories, Samantha has always been my favorite. It wasn't until last year that I realized they were actually discontinuing any of the dolls; I think Samantha may have even been the first to become archived, right? I think she was discontinued the year before I'd even learned any of them had been/will be discontinued. I was shocked and a little saddened because growing up I always thought, "One day, I'll save up enough money to buy the Samantha Parkington doll" but that never happened. Now that I'm in my mid-20s, is it too late to get a doll of my own? I'm considering Rebecca, but I still miss Samantha! The Samantha I saw on eBay (that was in mint condition) was being sold for $300+. Should I buy another historical American Girl doll now and consider it an investment? It makes me sad to think there might be some kids who never get interested in Kirsten's, Samantha's, or Felicity's stories just because there's no dolls to go with them. I know that sounds dumb but for a lot of girls--the American Girl obsession starts off with the dolls. Still, at least the dolls get them interested in learning something about their characters' historical backgrounds.