Noah earned $60/large painting x 8 large paintings = $<<60*8=480>>480 for the large paintings.
He also earned $30/small painting x 4 small paintings = $<<30*4=120>>120 for the small paintings.
His total sales last month were $480 + $120 = $<<480+120=600>>600.
So, his sales this month are $600 x 2 = $<<600*2=1200>>1200.
#### 1200