Hello, Has anyone got any experience regarding the Variable Amount feature under Item > Web Store subtab? I checked this box for an item, but I still cannot set price manually for that item on the webstore or via Commerce API. Am I missing anything?

Man, this is coming up a lot recently. Variable amounts are not supported by the Commerce API; there is no support for the 'amount' field and so any attempts to add an item with that property specified will always return an error. It is possible to use the generic add to cart end point, but we don't officially support it with SCA (although my personal opinion is that it is unlikely to be going anywhere anytime soon). If you want to write a customisation that uses it, that is your call. For more info, see https://system.netsuite.com/app/help/helpcenter.nl?fid=section_n2612472.html

Got it! Thanks for the inputs Steve.

You can raise a case and request that an enhancement request is made for it

Just to confirm, this will be an SDN case right?

I don't know what an SDN case is.