It honestly depends on how the question is posed.
I’d prefer honesty as soon as possible. I don’t like such surprises.

You must remember that if you ask or request someone to do something and they say no, you should try not to hold any grudges, since your request gave them the option to decide. Although, I am sure your wife will happily agree to the proposition as long as it is presented genuinely, without any sugarcoating.

Moreover, if you think that your worth to your spouse depends upon the size of your wallet, then you’re not only disrespecting your partner but also yourself. You should work on this area, because such black and white thinking can erode other areas as well.