I'd be very hesitant to do something that damaging to my hair. It's extremely expensive (I'm sure there's a range but I had a friend get them last year by a so-called "hairdresser to the stars" & it cost her $4K) and if/when you tire of them you're looking at additional expense to have them removed, plus a long time for your hair to recover.
Sometimes when we get bored or feel like we're stagnating we do dramatic things to shake things up a little (I'm guilty of this myself & boy do I have a long list of regrets). I'd recommend staying away from the extensions & maybe getting some pretty, summery highlights instead.