Sword replica question

Your question touches and concerns potential trademark infringement and patent law.  The operative question is whether the sword from the company that you intend to reproduce has a protectable trademark and/or patent.  If there are certain writings, potential copyright issues arise as well.  This area of the law is very specific and only a qualified intellectual property attorney with patent experience and licensure can provide sufficient advice. While there are always exceptions, the general rule is that the owner of property has the right to control its property.  Thus, if a company designs and manufactures a special product, such as a sword in your case, it has the right to exclude others from copying it.  The property laws, if violated, can be extremely harsh.  For example, a few years ago, I defended an individual who was accused of owning and operating a retail store devoted entirely to selling replica merchandise.  Needless to say, this individual was fairly successful as the products sold were listed at prices far below than what the originals were priced.  However, the store garnered the attention of a large manufacturer who sued under the Federal copyright and trademark acts, as well as a host of other common law claims.  The litigation was ultimately resolved but the cost to the individual was overwhelming.  Had that indivdual first consulted with an intellectual property attorney before going into business, the inevitable lawsuit would not have occurred.  Are there other companies selling replica items? Sure.  But going into this business blind is like playing Russian Roulette.  Just because another company is selling replicas does not mean that the company is doing so legally.  It very well could only be a matter of time before that company gets sued or even worse, criminally prosecuted.  I wish you the best of luck.