I didnt check the thread nor the user but even if he offers to use an escrow, escrow wont help you at all. If the owner of a voucher contacts the company the voucher is from, claims that his voucher was stolen then the money from the voucher will taken back. The buyer sits on the loss and the escrow cant do anything about it.
The only way that an escrow could help would be to find out how long the voucher seller could claim a voucher stolen. If the escrow funds, from a trusted escrow, are given to the seller only after that time, then you are safe.
So if you have doubts then better stay away. Only invest or buy if you are pretty sure that it will go fine.
But he's offering to buy the items directly, he's not giving vouchers.
Buyers should ask the escrow to hold the payment until the good arrives and is checked by them.
The only problem I see is the seller may be laundering money or something else illegal. Probably still not a good idea to deal with him.