When you press R twice, you get a two-toned whistle. Repeat as needed (in one day you can receive 500,000 Gold). Then, walk down to Van's and sell all 99. Keep pressing 'A' until you have 99 of them in your Rucksack. The Fishing Pole sells for about 1000 Gold a-piece.
Whenever Van comes to town, quickly go to the Tool Shed, locate the 'Fishing Pole G' and keep pressing 'A'.
This only works if you have the cheat (Action Replay) for 'All Tools in Shed'.
