Honestly I'm not sure where orokusaki and digital_shubhi are getting their definition of 'quality' from. Considering the first reply suggests having to religiously check for people trying to rip of you off, I'd assume they're not exactly setting the bar particulary high.
If you want well written articles that provide engaging and original, you need to pay for them. On average, a 500 word article should cost you between $10-$25. I'd say the $10 a minimum. I wouldn't work for quite that little and neither would many decent, professional writers, but you might get lucky!
There are plenty of content writers that advertise here that would charge over $35 for a 500 world article.
If you just want recycled content to submit to ezinearticles, you can probably get away with $5-$7.