Knight rifles website has the manual for this gun available to download, contains complete instructions and capacities for powder etc. www.knightrifles.com
100-450 USD
The Knight LK-93 was made from 1993 to 1999.
Contact the company at knightrifles.com
#11 cap originally but there are conversions for them to use larger 209 shotshell primers to ignit pellets better.
The best way to determine actual value is to search the on-line auctions, such as www.gunbroker.com and www.auctionarms.com or even www.proxibid.com enter your details in the search and see what is selling and for how much. You can also search the archives and or sold items to get an idea of what your gun is selling for. Another place to look is The blue book of modern black powder gun values, available from www.midwayusa.com as well as many of the other hunting and firearm stores. That will give you an idea of the general value. Guns tend to have some regional value too, say a Thompson Center Seneca may be worth a bit more in the north east than in the mid west. Don't forget condition has allot to do with value, so compare apples to apples.