1997 Corolla Battery troubles

[eggsampull]

Alright so here's the deal:
Purchased a new car battery for my 1997 Toyota Corolla about a month ago. About a week ago car would not start so I checked the battery and the terminals for both positive and negative sides where corroding (especially the positive side). I then cleaned off both terminals and both sides of the battery with hot water and baking soda. The corrosion completely removed I got another jump for the car again. I ran it for a while (unfortunately I do not have a battery charger) in order to get it charged, but this was to no avail. I then removed some electrical tape from the negative side and found that the cable had indeed began to corrode. I am thinking about buying new battery chords and terminals. Does anyone have an idea how much this should cost (hours and/or dollar amount)? I've never had my car serviced and I don't wanna get the shaft from local mechanics.