I'd like to buy a spare Magsafe 2 charger for my 2013 MBA, and I suppose I'll pay Apple's over the top $70 price if I have to, but I am wondering if anyone has experience with any of the third party vendors of similar Magsafe 2 devices that sell for no more than half as much. I've read of problems with the Apple charger and of course of problems with the third party chargers. $70 seems awfully steep a price to me. So, any recommendations...specific alternative brand names, suppliers, et cetera? Thanks!