famekrafts it's calculated as follows:
- You set a % off
- This % off it applied to all items in the bundle at their current sale price (rounded down to nearest penny)
- The total of this amount is charged
- On occassion, 20% is deducted as sales tax (VAT).
- Then, payment processing fees are deducted
- Then we deduct 30% as our commission
- The remainder is your profit
If you have a bundle AND an item in the bundle is also on sale, the bundle discount for that particular item is the sale discount or the bundle discount, whichever is greater. Just something to keep in mind.
Bundles are advantageous in that they encourage buyers to buy more items from you than they might of otherwise.
FAQ has some more details:
https://www.scirra.com/store/faq
(refer to "custom bundles" question)
If you have a specific question about a particular sale, send me an email with a link to the bundle and I am happy to go through it with you and make sure it's all OK.