I think that SFDC had a lower priced option previously. They are retiring Desk.com which is an online support tracking tool they bought in 2011 (then Assistly) and renamed as Desk. Presumably, they roll (or have rolled) the features into SFDC.
https://www.cnbc.com/2018/03/13/salesforce-essentials-launches-desk-com-and-salesforceiq-to-be-ended.html