There really is something rotten about someone getting raked over the coals financially in addition to emotionally. Some parts of divorce law makes it too easy for someone to profit when they are mostly responsible for the breakdown of the marriage.
Is it possible to buy her out of spousal support by refinancing the house? If so, offer lower than what you would pay out over time since she would not need to pay taxes on a buyout since it is treated just like division of assets in the eyes of the IRS. However, you cant deduct the buyout, but it sure was easier to refinance to be done with it. I was looking at a similar amount of $1800 and I would have had a hard time surviving after that.
Plus, at least in Oregon, if no spousal support is on the final D judgment, there is not way to have it added later. If it is on the D judgment, they can modify it up or down of change the duration depending upon situations that come up. For instance, I was told that if my XW were to become disabled that they could change the duration to indefinite.