Hold onto it. It can only get more valuable as time goes on since more are not able to be created. I've personally watched my Grandmaster go from like 16 bucks to over 100 bucks over the course of a couple years. Corpse carrier will likely do the same. I cant say it will be to the same extreme, but I cant say it wont be more extreme either. You cant find out without waiting.
You might be able to get somebody to buy it now for a decent price since there is a bit of a stir about it, but I imagine what they will pay you now will be peanuts compared to what you will be able to get if you wait.