Calling in the big box store technicians should always be a last resort.  The bad reputation that these outfits have gained does not seem to stop people sampling their services.    Once bitten twice shy may be the order of the day after the experience - but they have your money and you probably lost your data.  

My ethic is simple.   No fix, no fee (offsite only).    I also do not charge call out fees within 5 miles of the 77586 zip code, charge no evaluation fees,  and we have no hidden charges.   And most important - fixed hourly rates.