You should only ever buy a company from a professional adviser, or a reputable agent that they recommend to you. Otherwise you may find that the paperwork is improperly prepared. In the worst case, you could find that your company has existing liabilities of which you are not aware.
You should also be careful about the company's name. You could face legal problems if your name is similar to a name used by another firm in a similar line of business (see 15).