Hiring a freelancer is not that expensive. You can hire someone for a month for a couple thousands dollars, and a month is plenty of time to build a prototype if that's all you're doing.
If you say that you can't manage to come up with even $3000 or $4000, that tells me two things: first, you don't have any monetizable skills, so you don't sound like a very good person to build a startup with.
Second, you're not very resourceful, and that doesn't play in your favor as a startup co-founder either.
Sacha also goes into several reasons why freelancers are a better thing to look for, if you need help, rather than cofounders.
I think Sacha is spot on about those reasons, but he's missed one that trumps them all:
I don't think it's actually possible to "look for a cofounder", especially not if you already have a project under way. As I've pointed out before:
...networking to find a cofounder is like going to a party to find a wife. You might meet lots of interesting, and potentially eligible, partners while out networking/partying, but those who respond favourably when you mention what you're looking for on the first "date" are probably not the ones you want to marry.
Hanging around places where you might meet potential cofounders is great. Building relationships is great. Working on projects that you're both passionate about together is great. But going out networking explicitly to try and find a cofounder is misguided and will probably cause you trouble.
If you've settled on the idea already, it's time to get early employees, not cofounders. They should be paid. If you can't do it without getting other people's help and you have no money to hire others, then this is not the right idea for you - find one that's more within your reach, or build relationships with potential cofounders and find ideas together.
What you should almost never say is "I have an idea, I should now look for a cofounder".
A co-founder is not what you need, unless you already have one, and you have as good a relationship with them as the best relationship you've ever had with anyone in your life. If you KNOW you're not going to have a problem, then great.
If you read this far, you should follow me on twitter here.