The latest Journal of Personality and Social Psychology says we use visible luxuries and helpfulness in part as ways to attract mates:

Conspicuous displays of consumption and benevolence might serve as "costly signals" of desirable mate qualities. If so, they should vary strategically with manipulations of mating-related motives. The authors examined this possibility in 4 experiments. Inducing mating goals in men increased their willingness to spend on conspicuous luxuries but not on basic necessities. In women, mating goals boosted public-but not private–helping. Although mating motivation did not generally inspire helping in men, it did induce more helpfulness in contexts in which they could display heroism or dominance. Conversely, although mating motivation did not lead women to conspicuously consume, it did lead women to spend more publicly on helpful causes. Overall, romantic motives seem to produce highly strategic and sex-specific self-presentations best understood within a costly signaling framework.

This suggests that female luxury consumption, and non-heroic non-dominant male helping, are not done to impress potential mates.  Of course they could still be costly signals, but to other audiences.