Is this a correct sentence? - 1

"I would really love to sell my Nikon D40X camera to recover at least 10% of my new camera investition."

The sentence structure is correct… The word "investition" is not. I think you intended to use the word "investment", which would be correct.

Zoltan, I was not familiar with the word 'investition,' so I attempted to look it up. I found no such work in my dictionary. I think you might mean "investment," but I would suggest you end your sentence like this: "… To recover at least 10% of the cost of my new camera." Good luck.

It's a little confusing. When i read it at first I thought you were selling your camera to get your money back because you used the word recover which usually implies getting back. I think what you are trying to say is that you want the money you make from selling your old camera to be at least 10% of the cost of your new camera. So this is how i would say it.
"I would really love to sell my Nikon D40X camera for at least 10% of the price of my new camera."
or "I would love to sell my Nikon D40X camera to cover at least 10% of my new camera."