How does it feel to have a v-neck under your shirt? And more importantly, is it worth buying a high quality shirt for say $100 if you're gonna wear a v-neck underneath? You aren't going to feel the shirt anyway.
Shirt + a v-neck, how does it feel? Why buy a HQ shirt then?
If you like the concept - then choose your v-neck first and then try whatever fits over it to add that extra fashion.
Although this sample is v-neck with casual jacket - there are several good looking shirts that may be left unbuttoned near the top as well.