I've an 09 Muscle that I bought in 2010 with only 1,000 miles on it for $10,000 (a steal). Since then, I've ridden it over 40,000 miles and added lots of modifications (too many to list) worth $5-7K, depending upon what was added, when and whether I did the labor myself or took it into a shop to install. The bike is in very good shape with only normal wear and tear in terms of body and paint conditions.
I've periodically looked into selling it and would probably get no more than $8,000 tops for the bike. For me, however, it's not about money. I love this bike and now that it is nearing its 10th anniversary (it was made in October/November 2018), I'm keeping her! No divorce and no trading in on a new model of any kind! Nothing puts a smile on my face faster than getting ready to ride my V-Rod (except of course a little nooky from the Mrs. every once in a while...ok, TMI).