How much should I spend on a wedding gift for my brother-in-law?

Not the amount, but the spirit of welcoming him to the family. Spend what you can afford.

How do you decide affordability? By your desire or by your finances or by public norms?

@Qualityoflife360 for me, would be after looking at my checking account. Forget the public norm.

Is it a big wedding with a sit down dinner? Usually, if you can afford it, a bigger gift is given in this circumstance. A smaller wedding with just cake and finger food? A smaller gift. But really, give what you can afford. If you can give a 30 to 50 dollar gift, without making your life uncomfortable until the next payday, then do that amount.

Thanks for your input. It is a big wedding.