Yeah its a -huge- pain in the ass. In the same boat myself. Still a good 150,000 gold coins short. At this point I'll probably cave and buy 100k gold coins. First time I've played this and it was quite enjoyable, a tip in the tip jar of sorts and a giant fuck you to that last trophy. Shrug.
Why would waste any money on it? It's completely meaningless. :-/
Edit: top of the page (for Silver members) recommendation: go buy Motorstorm RC.