All major Silicon Valley law firms (Gunderson, Wilson Sonsini, Fenwick, Cooley) will defer your fees to get you as a client. You should negotiate at least $15k-$20k of deferral of fees if you are a startup, which means you won't cut them a check until/unless you get financed. They should also offer you a discount on their normal rates of 10-20%. And they may ask for warrants; up to you to issue these. They may pound sand, but if they really want those, then you should be getting a lot of legal work for free.
The vast majority of legal work they do for you as a startup is form work, so don't ever pay a partner more than a half hour to review it. 90% of the work is literally changing names in a document: incorporation docs, board notes, issuance of options, option plan, assignments of IP, and financing docs should all be standardized. I know this because I worked at Gunderson as an attorney.
What you want from startup lawyers is a clean form that your investors have seen before. Don't do anything that makes an investor think twice. Any form from the firms I mentioned above will do.
Net net: you shouldn't worry about $700/hour. It's too much, you shouldn't be hiring that particular attorney, and even if you do owe thousands of dollars, you shouldn't have to pay it until you're financed (which means you have the cash anyway).