Welcome to Stangnet Dan! Is it isn't Captain Dan is it???
You know, "Captain Dan" from
Forest Gump... Oh, never mind...
Anyway, Mustangs are an excellent cars for beginners to get started since they're affordable, and you can get darn near any part you'd ever need for them. As for how much to save, it really depends on what year, body style, and options you want. From the sound of it, you're gonna be on a pretty tight budget, which means you'll probably be in the market for a '65-'70 coupe (the 1970 looks like the '69). Probably for a decent project car, you can expect to spend anywhere from $1500-$3000. For this kind of money, you can score a decent little 6 cylinder, or a more beat V8 car. You can typically get a '69-'70 coupe with more options for the less than a comparable '65-'68 coupe. They also seem to have come with disc brakes and V8s more often too. Also, the '70 model has some good advantages with some better factory safety components like standard shoulder belts, colapsible steering column, high back seats, etc. Better cars needing less work, often in good running order with some work already done, can be had for $2500-$6000. Whatever you decide on, buy the absolute best car you can afford. More money spent up front almost always saves a ton of money later.
Whatever car you're looking at, look for rust everywhere! Typical rust spots are the floors, torque boxes, subframes (these cars are unibody, no separate frame), rockers, trunk, taillight panel, doors, quarters, fender apron, shock towers, battery area, radiator support, and the oh-so-dreaded cowl. You name it, it's probably got rust. Rust repair is expensive and time consuming, even if you do it yourself. If you pay someone else, a simple floor/torque box/seat pan replacement is often over $1500. Professional full quarter replacement often costs $500 per side minimum. Taillight panel is $300. If you do the math, you'll find that it is almost always better to buy a solid bodied car for more money than to buy a car with rust and fix it. Ask me how I know.
After you pick a car, the sky is the limit for what you can do. If you're planning an engine rebuild with some simple mods, figure on saving another $2000 if you do the work yourself. This should get you a decent, fun, durable little motor with good power (not gobs of power, but decent) with an aftermarket intake, carb, headers, cam. Big power costs big money, so you can save up later for heads, a supercharger, nitrous, etc., but plan ahead when you build the motor so you're not wasting your money in the long run.
Suspension and brakes is limitless also. A basic rebuild of both systems is usually around $1000 before any performance enhancements. Budget performance stuff includes bigger sway bars, urethane bushings, higher rate lowering springs, etc. These aren't typically much more expensive than OEM replacements, so it's often worth it to add them during the rebuild rather than waste money on OEM and then replace it later. If you want crazy improvements, there are all kinds of high performance re-engineered tubular suspension kits, but they're also crazy expensive. Plan on saving closer to $3k-$5k for this kind of stuff. Disc brake conversions are popular, and budget conversions can be done for $300-$800 for fronts or rears. Big aftermarket disc brake kits from places like Baer, Wilwood, SSBC, Brembo, etc., are typically around $1200-$1500 for front, and $1000-$1300 for rears.
Interior stuff can be reasonable or expensive. Stock interior restoration kits are typically between $500-$1200 and will have everything necessary to redo the interior and reupholster the seats. After market guages, seats, shifters, etc., get pretty pricey pretty quick.
There's all kinds of other stuff like tranny rebuild/conversion, rear end rebuild/conversion, body work, paint, etc.. It all adds up pretty fast. But the better the car you start with, the less you'll have to spend later, and the sooner you'll be able to start driving it.
Anyway, I hope this helps. I wish you a safe trip home and the best of luck in finding the right car for you.
Dan Welcome to the Watering Cube. 
To You and DB he tapped out his fingers with all his short Bio. 
