I have a calculation based on retail price that I need to set the Online price to. Do I have the ability to just set the Online price via the API?
Yes it is possible to set the online price via the API. This can be done using the Item endpoint. You can update the amount field within "Prices".
This doesn't work for my ecom api. Apparently I don't have such endpoint.
Instead of Items i have Products
Still I'm very interested in changing this price.
Correct, the support rep was referencing the Retail API and not the Ecom API. Looking in the Ecom API endpoint (https://developers.lightspeedhq.com/ecom/endpoints/product/#put-update-a-product) I don't see the price fields as being listed. Hopefully just a documentation oversight?
You can not change the prices in eCom for OmniChannel, as the information is pushed from Retail. If you have OmniChannel, you can update the prices using the Item endpoint:
For eCom stand-alone, you can use the variant endpoint: