That said, we quickly spent close to $15k to include: Employment contracts that included equity allocations, IP docs and contracts for two of our larger clients (the bonus here is that we can reuse the contracts that have been tailor made to protect us)
They can also provide financial help in other areas too, merket research, branding and general business guidence, all the stuff someone with a tech background might struggle with.
There are limitations to what their funding will cover, and they don't require any equity in return.
Then, if you're equally willing to throw yourself into the code and server setup, customer interaction, and the networking that goes along with starting a business, again, it doesn't cost much.
I like LLC's personally because they're simple, protective, and structurally transparent. Then again, I don't usually go out and seek investment funding. I like to startup out of pocket, launch early the agile way, and then fund development with revenue.
The correct answer is it all depends on your financing plans, importance of liability protection, projected income and team makeup. Consult a lawyer.