Bismihi ta'ala

I would strongly recommend you look into the functionality of mahr, as unfortunately many Muslimshave completely misunderstood what mahr/sidaq is for. 

Mahr is nothing but a gesture and tokan of the groom's truthfulness in his proposal for marriage, and once the nikah is done, you both live amicably, with utmost respect, love, commitment and mercy. 

Should you wish to spend some money on her, or take her to Hajj, or buy jewellery for her, or property in her name, or anything else, that is out of your good will, and can be used by both of you as an investment for yor future as a family. 

It does not need to be under the title of "mahr", and none of these things work as a bond or a security for the continuation of the marriage or good spousal treatment. 

Islam teaches us to keep distant from developing a materialistic mentality, and marriage should never be about money or wealth. 

And Allah knows best