What should I do?


Recently, at a brick and mortar audio dealer, I listened to a high-end moving coil cartridge.  It sounded really good, and I was impressed.  The retail for this cartridge was more then I wanted to spend ($4500), but to make a long story short, the dealer offered me a rare deal, ($2500+tax) brand new, so I bought it.  Got it home, and carefully installed it last night.  I listened to it for about 2.5 hours.  It is really good, but I don't think (at this point), that it's that much better then my old cartridge (at least, not yet).
Ok, so this morning I played around with the loading.  Better, but still I'm not happy.  Now, with only about 5 hours on this new Cartridge, I realize that it's not broken in yet.  I'm looking for input as to your thoughts on how I should proceed.
1.  Are cartridges purchased from high-end dealers returnable (I don't want to create any bad feelings with this dealer, since he gave me such a good price)?
2.  I was told 50 hours of break-in time for this Cartridge.  Should I wait the break-in period to make any decisions?
Any thoughts on how you think I should proceed are appreciated! 


louisl
Latest update.  
I now have 15 hours on my new Mutech Cartridge.  Two important performance increases have occurred.
One, at, or about 6 hours, the cartridge's bass has matured.  When I first installed the Cartridge, the bass was extended deep, but it sounded as if the bass volume had been turned down.  No longer, it is now both extended, and full.  Rich, and detailed at the same time.  
Secondly, at 15 hours, the stage is opening up, and extending way outside the edges of my speakers.  Depth (on recordings that have depth) is also improving.  Image specificity is precise...voices that are sung together, are heard with distinction.  Each voice being defined, and heard in its own separate space.
This is now turning out to be one great Cartridge.  Real improvement over when I first installed it.  With only 15 of the recommended 50 hours of breakin, I'm hoping to hear even more.  
This is really one hell-of-a-good cartridge.  I will update when I get to the 25 hour mark.  Again, thanks to all for your comments! 👍
20 hours now on the cartridge.  This Mutech Hayabusa is already beyond my expectations.  At this point, I just can't imagine how it could get any better!  I will update again after another 10 hours of play time.  
louis, Sometimes things require a little patience. I'm glad your cartridge is now blossoming and you didn't.... "we know where he can put it", in which I meant, back in the box and on the shelf, of course. Enjoy!
“20 hours now on the cartridge. This Mutech Hayabusa is already beyond my expectations.” 

So where are you now with this cartridge?  What cartridge(s) have you had in the past?  I’m curious about this cart and there’s very little user (or professional) info out there.  Thanks!