Alimony amount

I know that you cannot give a specific figure as to what a dollar amount may be for alimony but can you give a hypothetical guess based on the following. We were married for 30 years and our children are grown and gone. We each have our own car. We are dividing up the furniture and we are splitting the profit on the house when it sells and we have no other assets to split. She makes $30k a year and I make $55k a year. We live within our means and have not been extravagant in our lifestyle. The duration of the alimony is not a concern to me. We want to agree on an amount ourselves. We want to know what kind of figure the court would think is fair should they ever have to decide for us. Would it be in the area of $250 a month, $500 a month, a $1000 a month or some other amount. Again, I know that you can’t speak for the court but based on your experience of what you have seen from the court what would be your best guess based upon the above scenario?

The figure is based on the shortfall of the dependant spouse (when considering a reasonable budget) and the ability the support spouse has to pay after meeting their reasonable needs (based on a reasonable budget).