Your current store does the job
If your platform is not holding you back (sales, speed, inventory and payments all work), a migration mostly buys you new bills. We would rather tell you that on a call than sell you a project.
You are heading into your busy season
Never switch in the six weeks before your biggest selling period. Search rankings can wobble after any platform move, and staff need time on a new system. Plan the move for your slowest month.
A key feature has no simple equivalent
WooCommerce plugins, Magento extensions and custom code sometimes do something Shopify only does through a paid app or custom development. List every feature you rely on. If the replacement is an app, add its monthly price to the comparison; if it needs custom work, get that priced before committing.
Most of your sales happen on a marketplace
If nearly everything sells through Etsy or Amazon and your own site is a brochure, a full store may not pay for itself yet. Test demand first with a simple setup.
Your processing or platform contract has an exit fee
Check your current agreements. A long processing contract or an unexpired platform term can cost more than the move saves in the first year.
Nobody has time to run the new store
A new platform needs someone to learn it. If nobody on your team can spend a few hours a week for the first month, the move will stall halfway.
A quick way to decide
Write down three numbers: what your current setup costs per month, what Shopify would cost at your sales (see our fee-math guide), and the one-time cost of moving. If the monthly saving or the sales you expect to gain don't cover the move within about a year, wait.