They've been charging me $3.60 processing fee for an individual card. I only ever buy singles on ebay so not certain about multiples or lots.
I've only ever used their cheapest postage service, $4.99 flat rate for any amount of cards purchased on the site but this increases depending on how many cards you have added on consignment (e.g. purchased from ebay) and the total value you declare.
If I add 3-4 cards the postage might go up to $7.99 but I'm not sure about the exact pricing threshholds.
I've been using them for about six years and had more than 50 packages deliveres without incident. Usually get delivery to Sydney in 2-3 weeks max.
They will also email you a photo of your card upon receipt, but it might take a week to 10 days to add to your account. Same with shipping requests. A bit slow in processing but they probably have justification.
Overall, I can't fault the service, even with the price hikes (used to be just $1 per card).