$0. I don't see any application for it at all. SEO is a competitive term, but "Teen" immediately conjures up an image of Porn. Unfortunately, the 2 do not combine to make anything useful at all. Just two unrelated terms that were available. Don't feel bad, there are millions of those. Just because something is available that happens to have words in it, doesn't mean that it makes any sense or is useful to anyone. Some things are available for a reason. JMO
I have to agree, I see no benefit from that name. Teen in a name draws nothing but people looking for porn. I guess if you could find a meaning of SEO in the porn niche, you could attract a buyer for the name but otherwise I see no value.
Undeveloped, I agree with everyone else: $0. But... If you develop it, maybe into a forum or community for young developers, it could be worth a pretty penny...
Then...you have to make it that, to get any value out of it. You can't simply say, "This domain would be could for this." and immediately expect it to be of value. At this point you just have a domain, and a concept. Develop the concept and then you have a business to sell, if that is what you want to do. Concepts and ideas are a dime a dozen. (Actually cheaper)
Agreed... The domain, along with the idea, has potential... But the value will be derived from development...