Nope, you’ll lose a sh*t tonne of cash though doing it that way.
There is zero chance everything you have is exactly what somebody else wants, so nobody privately will buy it all.
And unless you want to get seriously scalped, no re-seller will buy it, as they’ll need to make a profit, but won’t be able to sell it second hand for any more than you can.
Drop of quick list of your weapons and major bits of kit in appraisal’s, but typically kit is about 50% of retail if it’s perfect, weapons 60-70%, again if perfect and unmolested. Realistically, anything you think of as “upgraded” in any way, or anything painted, will be worth less than a standard weapon.