AWP Boom Minimal Wear is a Classified CS:GO skin that was added to the game back in mid-August 2013 as a part of the Arms Deal Update. The AWP Boom is a part of the eSports 2013 Collection and can be obtained as one of the random rewards from the eSports 2013 Case, which requires an appropriate key in order to be opened. The skin is available in three different exteriors, them being Factory New, Minimal Wear, and Field-Tested.
When it comes to the value of the AWP Boom, the prices differ depending on whether it has been equipped with StatTrak technology, as well as the skin's exterior quality. The regular version of the skin can usually be obtained for anywhere between $40 and $200 depending on the exterior quality, while the StatTrak versions of the AWP Boom usually sell for around double the amount of the regular version.
You don't need more sell skins for real money; on DMarket you can trade CSGO skins for other skins.