E-bay for eggs. Button quail eggs can be found all day long. Finch eggs show up but not often.
Button:
https://www.ebay.com/itm/12-BUTTON-Q...YAAOSw7UBeO46u
How many eggs are needed per snake a month? Local old school pet shops would rather sell them then throw them out. Place a wanted to buy Finch eggs on Craigslist. You'll find some.
Good luck!