One of the big concerns many CRM users have is storage. Both Sugar and Salesforce.com limit the amount of data a company can store when they host on-demand to 1GB of data.
All three companies allow you to purchase additional storage.
Sales Force Data storage is $300 extra per 50MB per MONTH *
Sugar Data Storage is $200 extra per 1GB per YEAR no matter what kind of data
SalesLogix Cloud = 50 cents per month, per GB
Of course with Sugar and SalesLogix you always have the option to host it yourself, in which case there are no storage limits. SFDC has no option to host the application yourself.
*Note that Salesforce.com charges two separate data storage fees. $250 per GB per month for FILE storage (documents, pictures) and $300 per month per 50 MB per month for general data storage (notes and other organic info).