In the scheme of things the Oz magazines have never really paid that well. SC is (or was) (IIRC) $100/page, tax free if you claim it as hobby income. EA was more complicated in how it was calculated, but was similar overall.
That's might be a nice little side earner if you can churn out general interest articles that don't need much work, but if you design a decent sized project then the prototype costs alone could be more than you might get paid for the article. That of course dosn't count your time, and if you are used to getting say $50/hour in industry, you certainly wouldn't do it for the money. It is a labour of love for most, with the real benefit being the kick you get out of seeing your project published, or possibly selling kits or bits on the side. It doesn't hurt on the resume either.
But money aside, I agree, I've found my dealings with SC quite fruitful and will most likely continue to contribute every now and then, and I'd also encourage others to do so as well.
Dave :)