There is a veritable shit ton of of online backup providers. Just google it. Most of them are around the same price. The biggest issue however is the restore speed. If (when?) your drive crashes, it may take a while to get your data back in useful form. Unless you are worried about something very catastrophic it may be easier and cheaper buying an external hard drive or a NAS device for your home network. You can purchase 500gb of storage and the software to run it for a couple hundred bucks.
Now as a direct answer to your question, if you have multiple PC's you can use logmein Backup to backup between them for <50$ per month. It works very well.
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