Unfortunately from the picture you can't really tell how big or small he is. Maybe you can ask the Breeder to take a picture of him in their hand or next to something to get a better idea of size?

Here's a pic of my GHI when I got her at 55 grams.
http://i.imgur.com/esW3uYoh.jpg

And here's my 2 newbies at about 120-125 grams as another comparison.
http://i.imgur.com/iYEFIBDh.jpg

ON mobile so posting images is a pain. Hopefully the links work