The main barriers to entry in fashion retailing are as much structural as financial. These days, there are multiple outlets for retailing online, as well as open-air markets and pop-up stores—innovations that have reduced some of the costs for the retailer.
However, the industry is highly competitive, which means that survival, not just success, depends more than ever on being in the right place at the right time, with the right product at the right price. This make-or-break aspect is complicated by the speed of fashion, where inventories can change weekly, and accurate forecasting of trends for the next season is critical but depends on the manufacturing lead time.
Next, profit margins are usually very slim, unless the retailer can pick runaway exclusive successes that no one has quickly copied (which is rare). Excellent communication with the vendors is critical so that their creative vision is at least somewhat in alignment with what will sell.
Depending on where the retailer is located and their volume of business, there may be dealings with trade unions that add uncertainty and expense to the transaction.
A lot of fashion is highly dependent on professional networks, since the whole field is so risky. These considerations may not apply to the small-scale online shop that carries limited lines on a consignment basis. However, the small retailer these days is dependent on social media savvy, which requires its own skill set.
The multiple areas of expertise required, which are combined with the challenges of the industry and the need for a genius fashion sense, are the true barriers to entry.