The first thing is to decide if you want to be a franchise or idependant. Franchises have set building start up fees. All you have to do is contact them.
Inventory will be the biggest cost. Fixtures can be bought fairly cheap second hand. Labor is also very costly. Insurance, rent, utilities, phone, and accounting costs.
Your main costs will be, land, labor, and materials. The contracted builder will tell you labor and materials but most of the time you have to find the land.
Some costs would be construction of the store, furnishings, display tables and racks, purchase of the inventory, computer for sales, accounting system, security, personnel, etc.