If you've got a buddy who's an Interstate retailer they might be able to get you a deal. My yellow-top was purchased that way for about $110, normally around $170. The red-top we just got for the Trooper was $140 at AutoZone since we needed it and couldn't wait. I've seen some good pricing online as well but you've got to figure in shipping.

These things are great for jumping others as we found out at the last meet where three VX's lost their alternators. -x-'s red-top pretty much kept VX1 alive with several jumps to the parts store. I originally got my yellow to be used in my Trooper RS for lighting, winch and audio before moving it to the VX. In my Merkur I used a red-top in an interior relocation (for weight distribution) since it can't spill or leak. Still used a battery box for cosmetic reasons.