problems expressing my reply/it is not worth it

[goodstudent]

I have a buyer making a low offer on one of my product.

I would like to reply something like the price is too low and it is not worth it for me to sell it and it is more worth it to keep it for my own use. I would be looking for a much higher offer.

I am not sure how to say it properly. Any suggestions?

I am also unsure if there is a term like "it is not worth it" or "it is more worth it for me to keep it"

[SoothingDave]

I would simply state that "I couldn't possibly let it go for that price."