Tracking for an online store records the buyer's whole path: a product viewed, an item added to the cart, checkout started and the purchase. At every step the website passes the name, price and quantity of the items to the data layer, and GTM sends them on to GA4 and to the ad platforms. That way each purchase is recorded once, with the exact value and items, not as a number without a value or as two purchases.
The price of €2,500 excl. VAT is for a store with up to 200 products. We test the setup with test orders and compare the revenue in GA4 with the revenue in the store. The ads receive the value of every purchase, so campaigns in Google Ads and Meta can optimise for revenue, not only for the number of orders. For a store with more products, several languages or currencies, the price is on request and we set it after the call.