wel, I'm fairly well connected, so perhaps my experience isnt typical..But my case and axles were $50..the chuck was free, but my buddy didnt count the teeth, so now I owe him for the 3.55s..lol. As far as bolt in, if it's sold as a complete rear..It is bolt in into your car. you should have the small ujoint, so you could reuse that too. You would need the larger shock plates if yours are not for a 3" axle tube..The 7 1/4 ones are not that big..8 1/4s are I think. Your brakes will dricetly bolt on, backing plates and all, although a complete rear should have brakes, they would most likely need servicing to be safe enough for me to drive. Brake cables go with the brakes, as do the steel lines and hose. I do admit, this gives you small bolt rear axles, so you'd want to change them, but on a budget, you could make do for a time until the $$ comes in.
As far as buying the parts, I wqouldnt want a $17? sure grip..new or not. A good one is $300 at least, then theres the ring and pinion, and the install kit. so we're up to $600 or so, and if you cant do the setup on your own (it's not hard, but you do need a press at minimum..) add another $300 or so ($65/hr times 5 hours) plus oil, axle seals (best time to do them) and you're now at right around $1000. Realistic math sucks. again, IMO, an 8 3/4 full rear, even as a core, will be either close to the same $$ but much stronger, or a bit less with the small pattern left in place for a time. Obviously, just my choice, it's your car. I know I can break them....hehe.