WOW.... for a 6 year old bow that was cheap and unpopular in the first place.... I'm sure you'll be insulted when they offer ya $50 and honestly they would be hard pressed to sell it to ANYONE!
For decent trade-ins you need to be talking of top end models and then the best way to do business is to upgrade and trade-in EVERY season so as not to lose much. For example, buy a top shelf rig now for $1,000 and trade off each Spring from around $600.... this will allow you to shoot the best bows in the industry eacch season for only $400.
As it is now, the unpopular Diamond will be tough to resale the minute you walk out the door so trade-in will most certainly be a slap in the face this time next year. LOL!
Good luck