I wouldn't say you bought it....I'd say you STOLE it !!!! I've seen 2013 going for $14,000. A 2012 with a couple thousand km selling at a dealer in Oshawa for just under $16,000. A 2010 in Paris is $10,000.
AND you got a trailer with it !
Depending on the colour of you 2007 I'd lean towards keeping the 2012. You probably have a year warranty left on it (a dealer can tell you the original date of purchase) and is still valid for you. You could sell the 2007 for close to what you paid for the 2012 and have a "newer" bike. And likely the 2012 doesn't have the "whine" that your 2007 might. Strip off the chrome you've added to the 2007 and move whatever is missing on the 2012.
Standard stuff though...check the date on the tires, check for a leaky shock, brake/clutch and coolant fluids.
Is there a manufacturer name on the trailer? Or does anyone recognize the trailer and what would it be worth?