Spending for your wife for the sake of Allah earns you rewards
Messenger of Allah ﷺ said, "You will be rewarded for whatever you spend for Allah's sake even if it were a morsel which you put in your wife's mouth."
أَنَّهُ أَخْبَرَهُ أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِنَّكَ لَنْ تُنْفِقَ نَفَقَةً تَبْتَغِي بِهَا وَجْهَ اللَّهِ إِلَّا أُجِرْتَ عَلَيْهَا حَتَّى مَا تَجْعَلُ فِي فَمِ امْرَأَتِكَ