I agree with what everyone is saying here. Do not cut corners on probably the most important peace of equipment on your vehicle. Tires and brakes, you always want to buy quality parts.
But as a suggestion, you should browse and keep you eye on your local craigslist for deals on used tires. People are letting tires go for steal all of the time. Usually just because they want something else. Even if it's just something to get you by and in the size you want until you can buy what you really want. Heck the tires I'm rocking are CL specials. I bought five of them for $400 and they retail for $400 a piece. Last I checked I'm still at 12-13/32" and that's after I've been driving on them for 5 months.
Good luck man.