Hi, koonghx

I have not tried Taobao before, however there are few things to consider:
- Additional shipping cost
- Shipping damages/faulty parts
- Reliability study on other buyer comments
- Technical support from their community forum etc

Nowadays, everyone want the cheapest and the best quality of product.
But it always depends on your luck.
Lowest price I saw before is only RM1000, but I won't buy it.
Normal local kits would be around RM1400-2000, depends on the model/size you required.
For above RM2000, probably you won't consider to buy because you want the cheapest.
Bear in mind, cheapest is not the best; best cheapest is not easy to find.
However, "Everyone can 3D print at a cost!"
Hope you could buy and get shipped before April this year.

Welcome to the club!     

If you going to provide 3D Printing services, I think you should invest a good printer such as Makerbot or Ultimaker. Reprap usually needs a lots of modding, fine tune and calibration, which repraper love its process of building it.

In terms of resolution, I assume most printer, even reprap can go up to 100micron. But even at same resolution, the printing quality will be varied depends on the printer itself (x-axis, y-axis, extruder, hotend, etc).

So, if you are maker who like to learn how to build your own printer, go for reprap. If you are aim for business purpose, go for off the shelf printer. Just my 2 cents.

If you are getting a sort of skewed square (not true square) then it is likely due to the angle alignment between the X and Y frames. You might have to bend the X and Y frame so they are 90 degree adjacent to one another. You should get a set square as your 90 Degree reference when aligning the X and Y frames.
I agree with what cha.968 said about "Everyone can 3D print at a cost!". Its like a joke about Airasia, the more you pay, the better the service. The less you pay, the crappier the service. Also, the best cheapest may be out there but it is certainly not cheap in our currency.

You can jump right into the 3D printing business and provide the service to everyone but can everyone accept the service you are expected to provide?

My advice for a beginner is: go for a reprap, learn the necessary skill to operate and maintain a printer, get lots of experience from 3D printing hundreds of designs, learn to design your own 3D models, then after all that consider buying a good quality 3D printer and start your business. My 2 cents as a 3D printing service provider.

Also koonghx, welcome to the reprap forum, where we double as sources for sourcing 3D printer parts and support group... 
The list of parts and links for sources are scattered across this topic. Have to go back several dozen pages to find them. 

I got most of my stuff from Ebay, still alright but expect long shipping time. 

Kits always refer to the parts supplied without assembled and tested.
You could refer to blomker.com if you are in Klang valley (mention me Cha recommended  ); or 3dprinter.my if you are in Johor.
All the list of 3d printing in Malaysia, I did post before in post #345, dated Aug 7 2013.
https://forum.lowyat.net/topic/2249129/+344#