Look at this site:http://www.lancs-lookup.pwp.blueyonder.co.uk/
Note that the researcher is not available until after September to do look ups. Also, she may not be willing to do all those Bill of Costs. Perhaps you could revisit the National Archives in the meantime and see if you can find the actual charges or summary of proceedings. I think the Bill of costs only relate to the witnesses fees etc. But I am not an expert on this as the National Archives soon lose my attention span.
Perhaps someone else can advise you on how to focus this so you only have say one or two charges for her to find.
Good luck
Pat