Keep adding to this if you feel like it. I'm making a bunch to start. It takes...
2 million days (at 150 coins a day considering you won't be on EVERY day) to get 300 mil. for a party hat. (only 5,479.4521 years! runescape might be something people have NEVER heard of by then)
821,917.8 coins per day to make 300mil in 365 days (a year)
2,739.73 coins per day to make 1mil in a regular 365 day year (AMAZING!!!)
Get the idea? Good. Now, just make ones and make them amazing like the third fact!!