The costs and complexity of SharePoint makes it a less than ideal solution for small to medium sized businesses. Online Collaboration solutions are an ideal SharePoint alternative [1] because they bring SMBs the same feature set, but packaged as a ready to use, easy to set up solution, without the need to set up dedicated hardware or software. As an example, this document compares web based HyperOffice Collaboration Suite [2] to SharePoint, on a feature for feature, benefit for benefit basis.
Links:
[1] http://www.hyperoffice.com/sharepoint-alternative/
[2] http://www.hyperoffice.com