Well make sure you have your important data backed up, that should always be first priority.
When a cheap PSU dies, it can take nearly anything or everything with it so I usually start with a good PSU. Cheap PSUs often don't have good protections in place and can send a nasty jolt through the system taking out motherboards, cpus, ram... everything basically whereas a HDD, as long as you have it all backed up just takes some time/money to replace and get it back up running.
That aside, 70 for the antec earthwatts 380? It is usually 40 on newegg so you might want to check for another source, I don't know what country you are in but 70 definitely seems high. It is however 1 of my first choices for PSUs on typical business productivity type systems that aren't using high end gaming type components. I do like the 1TB Samsung Spinpoint F3s they seem to run 50-60 here so your price isn't far outside that range for that item.