Most of Vanguard's minimum initial investments are $3000 so it may be a bit pricey for some people. Additional investments are $100. The best thing to do is set up an automatic investment option from your bank for purchasing every month. Dollar cost averaging is the way for most people to go. You get fewer shares when the market is going up and more shares when it's going down. The market is approaching bear territory so now might be a good time to start or at least soon will be a good time.