There are several different kinds of stores selling apple products. Those who offer full service are Authorized Apple dealers, and are listed on the Apple web site in your country when you do a search for dealers. Generally a full service dealer must also provide Qualified service (People must be trained and certified). Minimum Volumes for discounts from Apple are over US$250,000/year -- so you must be serious and devoted to this -- it can not a "side business" or part-time.
There are also other arrangements where a company can be a value-added Reseller -- these offer their software/services in a bundle with new MacBooks. This program was intended for companies like those selling, for example, dentist-office software packages, but can sometimes be applied to companies that just add things on and may even run a store-front or online store mainly to sell a modest number of computers. But always with something added on to meet the requirements of the program.
Still others, like colorware.com, do things to your computer (dis-assemble it and paint the outsides) that make a regular warranty impossible. if you have them paint your computer, the original Apple warranty is no good, so they provide a "return to our company for service" warranty. [They buy "bulk" computers without warranty direct from Apple, and can reduce the total cost to you by providing a warranty themselves.]
Before you spend your money ASK the seller you are considering what their warranty coverage looks like:
is it full Apple warranty, good world-wide?
Is it return to seller for service?
is it no warranty at all?
what EXACTLY is it?
