I really can not say except that in the US it is not a good deal at all but I am pretty sure you have higher base prices in NZ. It is not a bad computer and has a strong processor but the graphics card is getting a bit old. I myself would want to pair that 860 with an Ati HD 5850......at least if I had a monitor of 1920 x 1080 or higher.
You will not be able to overclock this CPU if it is like all the other Dell machines I have ever touched. The hard drive is probably slow. The cooling will be stock. The power supply should be OK, but you can count on the other parts being marginal at best.
I recommend that you build it yourself. It is an experience that will bring you closer than you have ever been to your computer.
Here is a configuration that has the upgraded video, and quality parts:
Intel Core i7 860 2.80 GHz, $516.60
Gigabyte GA-P55A-UD3R Motherboard, $296.08
Cooler Master CM Storm Scout Gaming ATX Mid Tower Case, $202.13
Xigmatek HDT-S1283 Heat-Pipe Direct Touch, CPU Cooler, $84.08
Amaze Tech AM5850-DDH-1024D5 Video Card, Radeon HD 5850, 1024MB, DDR5, $525.42
Samsung Spinpoint F3 Hard Disk Drive, 1000GB, 7200rpm, 32MB Cache, $147.05
G.Skill Ripjaws F3-16000CL9T-6GBRH, 3x2GB, DDR3-2000, $413.42
Cooler Master eXtreme Power Plus, 700W ATX PSU, $170.35
Microsoft Windows 7 Home Premium, for 64-bit systems, OEM $181.79
LG Electronics GH22NS50 DVD Writer, DVD 16R/22W/8RW $52.65
I think you can go to shops, but they will charge you a big lump of money for doing it... So it is better to put it 2gether yourself.. Unless you have got very little experience with such things. Here in norway, everything is 40% more expensive than in america - a $1000 rig in America would cost like $1400 here...
It is just not fair. I looked at an i7-860 at Micro Center, my favorite local store, and they are selling it for us$ 230. for comparison, I know that Fry's, the other brick and mortar in my neighborhood will assemble components you have picked out for $69. I suppose you can do a search for local stores in your area.
As for assembling your own components, there is a huge Homebuilt forum here with people more knowledgeable than myself, although you can PM me if you like - we may have a timing difference, since you are more than a few time zones away.
There are stickies and articles to get you started, and it really is easier than you think. Just remember to push you memory sticks down hard until they snap in!