The members of the Governing Body get paid the same as every other Bethelite by way of Monthly allowance and Personal Expense Account (PEA). The PEA is based on years of seniorty and is capped off at a certain level. I can't recall the exact amount but I believe it capped at $1,500 per year. I'll see if I can find my old Bethel Memos Booklet to see what it says there.
That being said however, the GB are in a position to receive gifts from the brothers as they travel and (unlike their tipping habits) many JW's are VERY generous to the members of the GB and other high ranking members from Bethel. Gifts have included cars, trips, special bottles of single malt scotch, clothing, and in one case I know one GB member who was given a Gold Visa card for his discretionary use by an elder in Ohio, that said elder would pay off.
So they are not lacking for anything. So too with senior Bethelites, they receive many perks as well. I know many Bethelites who were paid to travel to some congregations in Canada and the US to come give a talk there. Or in some cases the Bethelite paid airfare and once there, everything was provided for them. The local congregations viewed it as a way to say thank you to the bethelite and to support "God's House."
To answer Yeru's comment. The Rand shares held by the Society have not yet paid any dividends (as of 2001/02 when I last checked this stock for payouts - this was when it had been only been raised 4 times on these boards as a new revelation - sigh). The Society is in postion to benefit from the shares should a dividend be paid but have not yet received any. They are non-voting shares as well BTW.
So the GB get their money from:
1 - monthly Bethelite Allowance, 2 - Any pensions that they may qualify for (gov't or secular), 3 - gifts from the JW's. They are also given special consideration, i.e drivers, and extra personal services (laundry dry cleaning etc) over and above other Bethelites.
Hope that helps.
Uzzah