Same query absolutely work fine and return results.Did you tried
querybuilder generated Xpath query in tools query console from crx/de to
verify that result is same at both
place?/jcr:root/content/we-retail//element(*,
cq:Page)[(jcr:contains(jcr:content/@jcr:title, '*cost*')or
jcr:contains(jcr:content/@jcr:description, '*cost*'))]order by
@jcr:scoreHere is result from querybuilder