Short Answer: The only expenses You must cover are a Shopify domain for $14 (one-time payment), and a $29 monthly subscription for Shopify.
You will receive a 14-day Shopify trial from Adsellr, so no upfront payment is required before publishing your website. Besides the Basic Shopify Plan, there are no other monthly costs that are essential. You must, however, purchase a domain for a $14 one time payment. If You wish to add any custom apps to Your Shopify store, then You might need to pay extra depending on the app.
- Paid Advertising (e.g. $100 per month)
- Paid apps from Shopify App Store (e.g. $20-$50 per month)
- G Suite ($5-$10 per month