bro, as the cock in the relationship your normally going to spend more money on the gifts.

things girls like for gifts tend to be on the pricier side. that said if your in a serious relationship why are u worrying about how much she is spending on you. get her what you feel like getting her and that should be enough. dont be wondering if she will spend more than 50 bucks. thats a shitty deal.

edit:

and the fact u just posted ur income is 5 times more than hers well that seals the deal even more. man up u make the money she doesnt. its not that she may not want to spend money on you, she just doesnt have the ability to do so as easily as you.