Though Salesforce wasn’t identified by name, SugarCRM execs warn that the API charges associated with some SaaS providers can sneak up on you as a rising cost (particularly where deep integrations are done). In a SugarCRM world, you install your own instance of the open source software (on-prem or in the cloud) or you have your own instance hosted by a SugarCRM hoster like SiteGround…and there are no limits on API usage (no maximum number of calls, no maximum # of concurrent calls). In contrast, Salesforce’s page on API limits and usage makes specific reference to such limits and says the following:
“The calculation of the API request limit based on user licenses is designed to allow sufficient capacity for your organization based on your number of users. If you need a higher limit and you don't want to purchase additional user licenses or upgrade to Performance Edition, you can purchase additional API calls. For more information, contact your account representative.”
However, mileage will vary. Due to the way SaaS providers’ multi-tenant architectures help to drive the cost down for each tenant (customer), SaaS offerings may, in the big picture, offer a lower total cost of ownership (even after the cost of APIs are calculated in) than running your own installation -- even of open source software that comes at no initial cost like SugarCRM.