Ok, after going through the same thing i have some info that can help. Firstly i was quoted $1600 each, plus 2 weeks shipping from Nissan. Dont know who you went through, but can you please give me their number because thats an awesome price for new struts!!
Secondly, I spoke to some airbag suspension places and they told me it would be $700 to get aftermarket airbags put on the OEM struts. Compared to the $1600 that was quite tempting (cos aftermarket bags dont mind being deflated).
Going through the any of the Yahoo Purchasing services was going to cost me about $400, and that was getting closer to my budget.
Finally i rang JustJap in sydney and they managed to get me one front and both rear struts (secondhand) for $250!! Really dont know how they managed that because I cant imagine shipping being so cheap. Only downside was the 8 week wait. But i have them now, and although they look kinda old, they seem to be holding up...
Anyway, as others have mentioned, you might be able to get coilovers for around the $1000+ mark from Yahoo auctions, but they all seem to be the JIC SF-1s and from what i have been told these are a brutally stiff coilover. Plus for me i *need* air sus because my front bar is only 1-2cm off the ground when the car is lowered just right...
If you just need something to get you by, i have been told that R31 skyline (Aus spec) struts fit. Only problem is that the brakes are much smaller, and its 4 stud instead of 5 stud
Another option is Z31 300ZX struts which are also supposed to be plug and play. THe turbo models had 5 stud, and similar brakes, but i believe they are kinda rare...