On Amazon you get the money when you claim you ship it. If I dont use Amazon Fufillment, I have 48 Business hours to ship it. If I use Amazon Fufillment I get the money when AMAZON ships it.
On eBay for new sellers its up to 21 days to get the money.
The way the know on Ebay is the tracking #, if you are a new seller if you upload to them the tracking # and then can tell when it was delivered. If the buyer leaves Positive feedback then its also assumed the item was delivered as well and you get them money