[Silver Ghost]

What would you replace it with?
Although you probably won't get back the $$ you've already put into your D, the major decline in resale value has already happened. So, other than maintenance (and of course potential major maintenance is always a possibility), it won't cost you much to hang on.
Obviously it's your decision. I can think of two major reasons to move on: cost of fuel and significant change in lifestyle.
As DurRT says, may want to sell the added components separately as they won't get you a lot of extra if you sold the D with them.

Joe