Saving up $5000 is simply not feasible for a lot of people.
I'm a developer today, and do ok by industry standards (not great, just okay, for now). However, I grew up in a less than trailer trash home, my dad was a janitor, my mom was nuts (I used to watch her talk to invisible people in a roach infested kitchen), my siblings were sucked into the poverty mindset. I was born with a serious medical condition. I've had some other crap go down that I'll barely tell my close friends, let alone an Internet of strangers, but trust me when I said I've had to rebuild areas of my life more than once. So what. I won't tell I have it all figured out, but I will tell you I will not be defeated. And I have little sympathy for those who tell me the horrible hand they've been dealt.
I realize that we live in a world where only the kids of the rich get to succeed, and the only way to start up your own business is to join an incubator. If you believe that, then you will be taken advantage of. Either push to be successful, or be the kind of person that the successful use to get there. They're more than happy to take your money and your spirit.
Doing that in a year or even six months is plausible, depending on how lucky his circumstances are, but three months strikes me as a bit of a stretch. At $10/hr * 40 hr/week * 12 week = $4800, ignoring rent, food, incidentals, and taxes.
If that were to become an obstacle, one solution may be to get a second job.
And yet the OP writes that he's having trouble getting even one of these jobs. It may be hard to believe, but some small towns have a vast, vast excess of people wanting these jobs.
I could also suggest he goes off to western north dakota to work in the oil field, but I don't know if that's such a great idea. I have some friends that have done that. It sounds horrible, and they look like they are about 15 years older than they actually are. Plus you need the money to get there, and need a car, all of which is probably $5K+ anyway.
How in the world could anyone save $5,000 in a summer when they're not even pulling in that amount?
EDIT: Even working 80 per week only brings in $7,680. Factor in bills and you're still not hitting 5k, guy.
Edit: What bills does he have? Food is free, because you work in food service. Rent in a place like Yakima is < $400/m. Summer starts in May. Also, after 40 hours a week you get overtime.
I've never heard of a food server job that hired fulltime workers or allowed those reaching 40 hours to go beyond that.