Good qouestion
There are more ways to invest 500$ in SFI business.One of them is to buy a S-builder unit and increase your chances to get affiliates who want's to work.
Other way is setting up a Standing Order to maintain your status every month.
The 3rd way is buying PSA'S to go on TripleClicks and make a strong team on your Down line.
And the last is using paid advertising to bring in new affiliates and build a team