Not saying your estimate is wrong but which model is that price based on? Are there more photos of the gun, particularly if there are any scuffs, scratches, etc, as well as the box to identify the model name/SKU?
"Not used much maybe 10-15 times" will be taken with a pinch of salt by a lot of prospective buyers. It's not to accuse you of lying or being rough, it's just not a reliable metric.