If you're hip to imagery and social media trends, or just find there's a shortage of decent shops in your area and are confident that you have (or can develop) the skills to make this work...go for it. The reason why I mention social media is there are no boundaries as to who can wear a wig or whether it looks great...ask Lady Gaga or Nicki Minaj. At one time, these looks were dismissed as being silly or childish but since people have come to accept this as the norm, it shows in the profits.
One good thing is that you don't have to have a cosmetology license or own a lot of expensive equipment or supplies to get started. Just having an idea of what will make your venture stand out or the idea client should inspire some new ideas. You can also cater to a group that's truly underrepresented in your local beauty supply shop like cancer patients, those seeking realistic-looking hairpieces, or those with large or small head sizes.
The Startup Costs
Depending on the audience you plan on catering to, initial costs can be low if you choose to use synthetic hair. This type of hair has many texture types that range from bone straight to extremely coarse (think of an afro or hair in a dreaded state). However, depending on the brand and style you choose, this type of hair has a relatively short wear life but is good for practice if you just learning how to make a wig or hairpiece.
On average, you can look forward to spending somewhere between $1000-2000 for supplies, tools, shipping accessories, and display materials. On the other hand, costs can be cut if you want to make a few hairpieces to test the waters. These take less time to assemble and costs less per unit so this may be a way to build your wig-making skills.