Today there are many different practices that have been "adopted" (not formally though) among the various Jewish communities on how the parents of an engaged couple divide up the expenses of the wedding - and potentially the couple's expenses as they start out.
In some circles, the larger financial burden falls on the parents on the girl. Often the boy's parents pay for a specific set of expenses (i.e. FLOP, Flowers, Liquor, Orchestra, Pictures). In other circles, the parents always split it 50/50.
Do the sages ever discuss what the proper approach to this important time is? Do we know how the sages and great Rabbis of more modern times dealt in these matters?