quality is quality- doesn't matter where it came from or how much you paid for it- there is no way for a judge to know if you spent $12 a yard, or if you spent $2 a yard-
if someone uses (cheap-as in low quality fabric) that is loose weave, doesn't hold it's shape, is apparently yukky- the quilt is not going to win any prizes- it may be critiqued about fraying edges, wavy seams, ect...
if you pay $1 or $2 a yard for decent fabric the quilt may win prizes- it really does boil down to the quality of workmanship & technique along with visual appeal.