The only reasons for RAID 0 are for space or speed. As your combined space is only 320GB, you could simply buy a 500GB hard drive and avoid the RAID. If it is for speed, then it makes sense, as long as critical data is backed up.
From the perspective of one who provides data recovery services, the odds of a drive crash in RAID 0 doesn't jump up from 1% to 9%, as each drive's odds of failure remains the same. So, your odds would, at best double. However, the cost to have a professional data recovery service recovery from RAID 0 can be more than double that of recovering from a single drive. The actual cost differences vary between labs.
Back to the backup. If your data is important to you, you should have a good backup routine in place whether you have a single drive or a rack mounted RAID 5 server.
From the perspective of one who provides data recovery services, the odds of a drive crash in RAID 0 doesn't jump up from 1% to 9%, as each drive's odds of failure remains the same. So, your odds would, at best double. However, the cost to have a professional data recovery service recovery from RAID 0 can be more than double that of recovering from a single drive. The actual cost differences vary between labs.
Back to the backup. If your data is important to you, you should have a good backup routine in place whether you have a single drive or a rack mounted RAID 5 server.