Most smaller firms will require a retainer. $5k is fairly common. I've been able to work with several large firms for work, and several smaller firms for personal stuff.
Personally, I much prefer the larger firms. In general their work product, responsiveness, and timeliness is well ahead of small firms. They aren't even that much more expensive for some things. Unfortunately I don't know what the retainer $$ would be, if any, for a larger firm.
> bootstrapped startups from underprivileged people.
i dont think startups should be paying a retainer. You do this only after it's worth the money - ala, you either know your domain is a gray area and is definitely going to require a lawyer.
This has nothing to do with underprivileged people or not.
This might depend on where you are. In my area, it's unusual to have to provide a retainer at all unless you're doing something big or the lawyer suspects you might have trouble paying your bill later.
Personally, I much prefer the larger firms. In general their work product, responsiveness, and timeliness is well ahead of small firms. They aren't even that much more expensive for some things. Unfortunately I don't know what the retainer $$ would be, if any, for a larger firm.