My wife keeps comparing me to her deceased ex?

I wouldn't.

Apparently, she married you just to be married and perhaps to have some financial support

No, it will get worse i see no future for this marriage.

I can't tell you what is right for you.
But I will tell you what I would do.
I would go live with a friend for a bit and still help with the bills.
Let her see what it like without me.
Then see if she appreciated me enough
to stop comparing me to her deceased husband. If not?
I would tell her to make other arrangements for the bills.
Then move out and file for divorce. I would rather be alone.

That's not right she needs to let her past go

Sorry, but it sounds like she is doing her best to ruin your marriage. It's extremely unfair and disrespectful to compare you to her former husband.

Hi! Seems like a pretty uncomfortable situation. I recommend going through this with your wife, and expressing how it makes you feel. I know it's easier said than done, but honestly, honesty is the best policy. Also, if she is saying things like that, I understand that it may be heartbreaking, but there's probably a reason, so talk about it.

When you are an adult ... you don't run away from adversity. You seek a resolution. And in marriage you seek a resolution together by talking to each other. And if you lack this ability, and many do, you seek a third party to help you relearn to communicate and resolve your issues.

Just ask her if she's happy with you. She'll ask why then there's your opportunity to say what's bothering you.

Be glad he was such a great guy. Ask her how you can become better like him? Probably she is forgetting his wrongs and mistakes and flaws.