Don't play their games ... tell the buyer to open an escrow at escrow.com with the *buyer* paying *all* escrow fees.
It's important that the buyer is the one initiating the escrow ... and in this instance, it's important they pay the *entire* escrow fee - in most cases, it doesn't matter much, but I have a feeling they're playing games ... you don't want to be get stuck owing escrow.com money; yes, technically escrow.com says they'll go after the party that backs out, but in reality, don't count on that ... cover all the bases - and really, if they're offering $100K or whatever, they can afford an extra ~$1K or so.
In a nutshell, sit back and respond with little more than "open an escrow at https://www.escrow.com/" and leave it at that.
Good luck
Ron