Tonight I was driving down young street and suddenly lost brake pressure. I managed to pull into a plaza, and noticed a significant amount of brake fluid leaking from the center rear area of the car.. It appeared to be a line leaking that went into some sort of distribution mechanism near the rear center. I've done manifolds, fuel injectors, brakes, exhaust, etc, but brake lines are new to me. I had it towed to a shop that's given me decent deals in the past.

Just wondering what insight the problem could be, or the average cost of brake line replacement (judging from the rust, the whole line probably needs replaced)

 

I would first check it's security at all it's fittings going into that weight bias/distributor block b4 replacing anything...you may have a loose connection. Inspect your brake hoses and if they're soft or dry rotting, invest into some Goodridges SS braided hoses (best thing since sliced bread)!