I usually face this situation where most of the teammates I play with always buy during this round. And if we lose, this results in a 11-12 where we can only half buy and the enemies will definitely full buy. If we're lucky, we can bring it to overtime. But usually, this ends in a loss.
Thus I want this round to be a save, to have a higher chance to win the next round with better weapons and bring it to overtime.
The only time I would buy in an 11-11 round is when I have enough for a full buy in the following round.

But in my elo, almost everyone buys in this situation.
Isn't it always better to have higher chances of winning the game, rather than relying on your skills?

What other economy situations do you face? And what do you do during that?