Hi hope someone can help me before my brains explodes!

I will be attending my first trade show, at the British Craft Trade Fair stand N40, I do know how to price invidual items,
but because my jewellery are one off designs, I have been advised to price my items the same price by jewellery range, so if an item of the same collection is £275 trade, and another is £360 so my average would be £317, ? so I will loose on one but gain on another,

Does anyone have any advise? how to price one off designs, for the retail to order (lets say 10 items) without them even seeing some of the jewellery,

so for insance- my pretty wild collection, all the same flow but different designs, added gold, larger, smaller, my head is battered.

how would you do it?