Such a large sum of cash would require a face to face trade, maybe a legal sign of some sort, Please have a brief look at the bitcoin history!
As an escrow agent, I will say this! Dont use an escrow that cant cover theft, I would never take this on as I could not cover the loss if someone hacked me and stole the coins, all my escrows are covered by my word, If I loose your coins I will pay you out of my own pocket.
This is an awesome deal for someone, I just cant afford that, but I wish you the best of luck, I will watch and hope everyone gets a smooth transaction.
I wouldn't consider doing the trade without a hefty amount of paperwork.
Yeah an escrow helps both parties but I just don't know anyone on here I can trust enough to do so. Not saying there is not trustworthy people just that I have never really been involved in trading/escrow on this forum.
If someone puts in a bid but requires certain procedure, be it escrow, lawyer etc then I'd be happy to sort that out.