Is oil painting worth something by James Mastin?

A oil painting by James Mastin was handed down to me when a family member ped away. It seems to be 38x30 size. The painting is of Attilla the Hun. Its labeled on the back side - illinois Moulding Co. Windsor Art Products. Hand written on the label - CB6024-420 The Golden Helmet. Signed on the bottom right hand corner of painting - J Mastin. Some appraisers online are asking me to give them a pre-conceived notion on how much i want for it. Can anybody help with the value?