Maybe its a round number in Riyals ?He doesn't go unless he's sure there's a deal coming so he cashes in twice.
His business interests are far too entwined with the individuals behind the SSG investment and he stands to make a lot of money maintaining those relationships; similarly, SSG's $3b is an investment with returns expected (at least in terms of value) so losing McIlroy at this stage is not viable for the PGAT or SSG, unless there's a deal coming. Selfishly, if he wins the Masters he may have considered it (if such an offer even exists), but as things stand, and with the associations he has established, it's unlikely.... and $950m is an odd amount, surely at that point it would just be a straight $1b?