Hello,
Selling 40k BTC. ONLY SERIOUS BUYERS.
The process:
You are represented by a law firm so you will be using your escrow attorney.
The basic is the buyer puts up a security deposit for the tranche size (which could be $1M-$3M+) with the seller's law firm. The security deposit does not move.
Seller sends coins first on an invoice. The buyer has 24-72 hrs to pay. In the event buyer does not pay an invoice, he'll go after the security deposit.
The buyer pays the invoice, the seller will continue to send coins and repeat.
When the buyer wants to end the deal, he let's seller know and his security deposit is returned.
coinbase price (negotiable)