In focus
The thing every Shopify store in Bangladesh has to solve: payments
If you remember one thing before hiring a Shopify store development company in BD, make it this: Shopify Payments does not operate in Bangladesh, so the default checkout that works in every foreign Shopify tutorial will not work for you out of the box. This is where cheap or inexperienced builds quietly fall apart. A developer sets up a gorgeous theme, the store looks done, the client pays, and then the first real customer tries to pay with bKash and there's nowhere to do it.
Solving this means deliberately configuring local payment options, either Shopify's manual payment methods with clear bKash and Nagad instructions, or a third-party local-gateway app, and then actually testing an order end to end. I don't hand over a Shopify store until I've watched a test order complete through each payment method you'll offer, because a checkout that's never been tested in BD conditions is a checkout that's broken.
Then there's the money question every BD seller asks: Shopify-er jonno koto taka, monthly and one-time both. The one-time build is the part I quote, and Shopify store development with me runs 50,000, 90,000 and 1,50,000 BDT depending on how many products you have, how custom the design and theme work is, and how much payment and delivery configuration you need, with fully custom builds from 3,00,000 BDT.
Terms are 50% advance to start and 50% on launch, with the store approved before that final payment. Separate from my fee, Shopify itself charges its own subscription in US dollars, which you pay Shopify directly with a card that can bill in foreign currency, and I'll walk you through exactly what that costs before you commit so there's no surprise.
If that recurring USD fee doesn't suit your plan, I'll say so and point you at a one-time WooCommerce build instead, because the right platform is the one that fits your store, not the one I'd rather sell.