In the original Pokemon games, the bike costs a ridiculous amount of money. So after first encountering it you keep playing the game until you come across a man who has a bike voucher. My question is, can you instead earn enough money to purchase the bike, and get it that way as opposed to using the voucher?
It is impossible, the bike costs 1,000,000, but you can only hold 999,999.
The Bike Shop has a store in Cerulean City, which sells Bicycles produced by the company. Designs range from a plain city bike to fast mountain bike; however the player only ever gets one: the Bicycle. It can be bought for 1,000,000, or exchanged for a Bike Voucher. However, as only 999,999 can be obtained at any time, there is no way to buy a Bicycle without a Bike Voucher. The Pokémon Fan Club Chairman in Vermilion City will give out his Bike Voucher, making this the only viable way to get the item.
Source: Cerulean City