Hiya, I'd link costings to your book keeping system and best practice possibly to a or more policy/ies on the reasoning you have behind purchasing and fees, and a box or folder that you keep all your product and equipment manuals in - guides, copies of reciepts, cut out information from discarded boxes / packaging? this would help show kite mark and standards information without necessarily having to pull out lots of your toys & resources's packaging.
Showing how you evidence costings can be to explain how your fees & charges are appropriate - what they might be based on - minimum wage (which is best practice in its own right), cost of food, materials, travel, time, rental rates of local facillities, regular or impromptu outings, entry costs for activity centres or other places... how you evaluate that and evidence how you provide a cost effective service could be via forum memberships, online and offline occasions where information may be volunteered by friends, colleagues, networks and other professionals - information purchased via professional memberships or subscriptions - ncma, insurance, catalogues, magazines, papers - how this, if a cost, is in itself evaluated for value.
Policy about how purchasing decisions are made - how you may research price, conduct product comparrisons, use recommendations, examine the quality of items, branding and how you might evaluate the resource's worth - using prior experience/knowledge or maybe if it's a new resource/food if you, the children & parents enjoy it, what feedback there might be and if you feel the resource delivered what was expected - more maybe or less ..
Kite marks should be found on or with safety helmets, car seats, pushchairs or buggys, buggy boards, larger sit and ride toys, bikes & scooters, trampolines, climbing frames, ladders, slides & swings, health & first aid items ... if you have a look at the kitemark site you'll be able to identify more things that you may have & that has kite mark information attached to it -
www.kitemark.com
CE mark information from wikipedia - other indications of quality marks can be the manufacturer details included on products/toys, such as codes, logos, safety instructions - Showing how you look for standards information on packaging/products as part of your overall buying and provisional approach could also be included in a purchasing & fees policy/procedure and where second hand purchases are made how you research the item prior to buying so as to know what you're looking for ..
Hope this helps a little, very interested to hear others ideas ..
Best wishes for your meeting
xx