This is a very strange one and I haven’t been able to find anything here on the forums about anything similar…
I just had notification of an order for an item that has 2 variations - one priced at £17.50 and the other at £22.50 - both are set for free UK postage.
The UK customer has ordered one of the items at the higher price point and has paid £40 for it via PayPal.
I have NO idea what has gone wrong or how this can even happen! If you have any insight, I’d love to hear it but I have sent a query to Folksy support and will post the answer here when I get it.
I think the second price is assuming the second item is £17.50 plus £22.50. Hence £40.00
When setting up choices you show the difference in costing for the dearer option in this case £5.00. If the same amount do not put in a charge and they will only pay £17.50.
Oh lordy - how thick am I?! 
That’ll learn me to read the sodding ‘how to’ rather than assuming that how the page appears when you’re listing is going to be straightforward! You’re only prompted to enter the “Price” next to a variation but I now see from the Folksy help page on variations that the customer actually sees it as a + addition.
Thanks so much for illuminating so quickly Caroline 
Took me a while but at least you have it sorted now.
