The daily rate for a contract GLEX Captain is $1200-1500 per day plus expenses domestically. Abroad you can get a GLEX captain for closer to $800 per day (ex-pats don't pay taxes). That's ICP pay.
For fulltime-FO pay in a GLEX I can only reference the NBAA salary survey that states median GLEX FO pay is $87,672, plus benefits. So that should be a minimum; as most companies, if they can afford a GLEX, will try to upgrade you to GLEX captain as soon as they're able. The NBAA salary survey puts the median GLEX Cap pay at $141,325.
On the corporate side of the fence, salaries can be all over the place. Large corporate (Gulfstreams, Falcons, GLEX's, Challengers) guys can make anywhere for the low $30's to well over $200K. Fortunately there are relatively few GLEX's out there so they still tend to pay rather well.