Hello m.a.y,
I can most certainly help you out there with economics, mathematics and advanced english.
More specifically for economics - I really REALLY love this subject. I know the course back to front. I've not only excelled in my school assessments (ranked 1st) , but have helped out alot of my classmates with problems they've encountered. I also regularly post in the eco thread on BoS. I reckon I'm exactly what you're looking for in terms of quality; I've never lost a mark in an economics essay (so I can show you what a 20/20 essay needs, and help you refine your essays) and I have an extensive conceptual understanding of the course, enabling me to effectively critique your work, and help you understand the key concepts. I am also in touch with current economic developments in the world, and have plenty of resources (worksheets + practice papers) that I am able to share.
As for prices, its $20 p/h at my place, $25 p/h if I'm required to travel, and this is relatively inexpensive in comparision to some of the other tutors in this forum.
More info about my marks + what I offer can be found in the link in my sig. Just PM me if you have any questions/are interested.