At first it takes getting used to counting in 1000s of dollars. There are notes in G$1000, G$100 and G$20 denominations. There are G$5 and G$10 coins as well. G$1,000 doesn't buy very much. The reason there is no larger denomination note is to discourage forgers from making the effort of creating fake notes.
It was impossible to buy Guyana Dollars in the UK. In general, bring US Dollars or UK Pounds when travelling here from the UK. Travellers Cheques actually give a worse rate and are only exchanged at banks, but have the plus of being safer to travel with.
If Guyana was bad, Venezuela was ridiculous. There everything was being counted in 10,000s rather than thousands. Plus we were trying to cope with handling transactions in Spanish. ('La quenta, por favor' - The bill please). Getting hold of Venezualan currency in Georgetown was tricky. Trinidad & Tobago had cents which took some getting used to. They also have TT Dollars fnaar, fnaar.