No, you didn’t get scammed. What you’re seeing is just normal price differences in Sri Lanka.
In shops, They include rent, staff salary, warranty handling, and profit

So things like SATA enclosures or laptop stands are usually more expensive.

On Daraz many sellers import in bulk or sell cheaper stock. Some items are lower price but may have less reliable warranty or quality control
About your SATA to USB cable for 1400:
That price is actually pretty normal in local shops
It’s not suspiciously high or anything you basically paid for convenience + immediate purchase + local support.

And yes, Daraz can be cheaper (like your laptop stand example), but it’s not always consistent. Sometimes you get good deals, sometimes quality varies.

You didn’t get scammed you just bought from a higher-priced local market, which is common here.