Bianchi Vigorelli...is it worth it?

Hi to all!
I'm I'm facing a serious predicament, and any advice would be greatly appreciated.
I'm not what one would call a "serious" cyclist. I just enjoy riding whenever I have a chance...usually 50-70 miles a week.
Until recently, I've been content riding a very old, but sturdy (and heavy!) Motobecane. However, as I've gradually become a stronger rider, I feel as though the weight and flaws of this bike are holding me back.
So I finally gave in, and while at the local bike shop, I tried out a few higher end frames. Among them was a Bianchi Vigorelli. It was love at first ride 😄
However, I'm worried that it's not worth spending this much money on a frame taking into consideration the fact that I'm not serious rider. All I really want is a comfy and speedy bike that will serve me well for the next five years without too many problems. Since I don't know all that much about bikes....I have no way of knowing whether this bike will provide what I'm looking for. Even though it felt perfect when I rode it, I have no way of knowing how it will feel after 20 miles.
Any thoughts or suggestions?