If budget is the real issue, consider free alternatives that offer similar (though less advanced) functionality:
If you want to test PrimoCache forever, run it inside a Virtual Machine (VMware/VirtualBox). Install the OS, install PrimoCache, take a snapshot. When the trial expires, revert the snapshot. This is perfect for lab testing but useless for your daily gaming PC or workstation. primocache trial reset license key
Many "trial reset" tools found on file-sharing sites contain malware or trojans. If budget is the real issue, consider free