How much does it cost to use the Shopify platform?

There are 3 pricing plans:

• $29 per month
• $79 per month
• $300 per month

Until your business is growing and you need to add more than 2 employees, the $29/m is sufficient for your needs. 

In addition Shopify charges 2.9% + 30¢ USD per transaction to serve as your merchant processor, allowing you to take credit cards on your store. 

You can see all the pricing tiers and rates at this link https://www.shopify.com/pricing.