Building an online store: catalogue, payment, and what actually sells

Building an online store looks like adding a buy button. In practice it is setting up the counter, the stock room and the till. If one of the three fails, people arrive, look, and leave.
Use this note if you sell a physical or digital product and you are deciding whether a catalogue without payment is enough, or you need orders, shipping and stock. For a store we have shipped, see the projects.
A store, or only a catalogue
A store pays off when the order can close without a phone call: a clear price, clear shipping, real stock. A catalogue is enough when each sale is negotiated, the product is made to order, or the ticket needs a conversation. Putting a cart on that second case adds friction and abandoned checkouts.
Many businesses in Valencia need both layers: pages Google can find, and a short path to ask for a visit or a quote. That is not an unfinished store. It is a lead site with the product visible. The price of each path is in how much a website costs.
The product page is the page that ranks

The store homepage is rarely the page Google shows. The product page is: the name, what it is for, size, materials, lead time and a visible price. A generic title (“Product 12”) does not compete with someone who names the piece the way the customer searches.
Photos have to read on a phone, with detail and without absurd weight. A gallery of ten 5 MB images kills speed and, with it, ranking and patience. Fewer photos, better ones, and text that answers the doubt before the button.
Payment, shipping and tax
Payment should offer what your customer already uses: card and, depending on the ticket, other local methods. Each method has a fee. Hiding the shipping cost until the last step is the most common reason a cart is abandoned. The time and the price of shipping belong on the product page, not only in a terms PDF.
VAT, invoices and returns are not a footer. If you sell to people and to companies, or you ship outside Spain, decide that before the checkout is designed. Fixing it later means redrawing screens that were already accepted.
A platform or a custom build
Shopify or another closed platform fits when the catalogue fits its logic: variants, discounts, shipping apps. You pay a fee and you accept its limits. It pays off if you want to sell soon and the process is standard.
A custom build pays off when the store has to talk to your stock software, odd price lists, a configurator, or a trade area. It costs more at the start and stays more in your hands. Choosing “custom” for prestige, with twenty similar products, is usually extra money. If you also need an app to repeat the order, that is another product: see website or app.
After launch
A store with nobody updating prices, photos and stock becomes false in a few weeks. Maintenance here is not a luxury. It is what stops you charging for a product you no longer have. It is also who checks that payment still arrives.
If you are at that point, or still deciding, write from contact. We count product pages, payment methods, and whether a platform or a custom piece fits. The audit, if you already have a store, points to three concrete brakes.
Questions
What do I need to open an online store?
Products with a name, a price and a photo, a way to get paid, a shipping and returns policy, and someone to keep the stock honest. Without that, the design does not sell.
Is Shopify better than a custom store?
Shopify fits a standard catalogue and selling soon. Custom fits when stock, pricing or the process does not fit a platform. We decide from the real product list, not from a brand preference.