Terrible compairison.
Can you do it ? Yes. Is it a great idea ? No.
The reality is that a set of springs is fairly cheap and a set of socks/struts is relatively cheap but not as cheap nearly as cheap as a set of 4 springs. Front AGXs are 120 x 2 = 240. Rears AGXs are 90 x2 =180. Thats $420 + tax and shipping for a set of 4 struts/shocks. A set of 4 coil springs like the Ford C springs are $160, Eibachs are like 240-260 or so and H&Rs can be had for around $250 as well. So lets say 240 for some nice AGXs and another 250 for H&Rs/ Thats 490 plus tax/shipping. Or you can go with a set of Ford springs for 160 + tax/ship and be done with it.
Which springs are you going to switch to ? If you are going to say the Ford C spring then you aren't as likely to kill your dampeners quite as fast as they wont slam the car and over work them too much. If you want to buy some Eibach then you will likely need fronts really soon and rears about a few months later.
Another thing, do you do the work yourself or pay a mechanic to put your parts in ? If you pay a mechanic then you might as well do the front struts at the same time since it adds all of about 5 minutes of work total for the fronts. The rears will add a lot more time and can be done any time down the line.
I think the most important question of all is, what are you trying to achieve by lowering the car ? Just don't like that "4x4" look ? Want better handling ? How rough of a ride are you willing to endure to get what you are after.
One last piece of advice. Stay the hell away from the Eibachs. I got them on my daily driver and after about 2-3 years I'm geting rid of them for some H&Rs. I'm just sick of scraping on everything, effing up my paint and having a VERY uncofortable ride..... they do handle quite well tho.... I don't think I'm "geting to old" I think I just shouldn't have to compromise this much for performance.