You cna upgrade to Workstation 8 for free on the VMware license portal:
1.Log into the VMware License portal using your VMware.com account credentials
2.Locate the VMware Workstation 7 product name for the license key(s) you would like to upgrade
3.Expand the product name and click the "Upgrade" button
4.Follow the prompts to upgrade your license key(s) to VMware Workstation 8
5.After receiving your new license keys, you can download VMware Workstation 8 software from the Workstation Download Page