Arun Sundaram joins Morning Movers to preview Costco (COST) earnings which report after Thursday's close. He doesn't expect any surprises on revenue, but is looking for a membership fee revenue beat after the wholesaler increased its fees. Arun believes operating expenses will be the big wildcard after Costco extended the 1-hour early opening back in July for its Executive Members. He says investors could be wary of the company's valuation as it hovers below $1000 per share.