My advice would go as follows….If you are going to go for the buyout, try to get the best deal you can. She will most likely balk because she most likely does not know how bad the situation is down here. So if you cannot get a good deal, try to actually put it on the market and sell it at whatever you were going to buy her out for plus all of the closing costs/commissions. If the house sells then great…if the house does not sell, then buy her out for an even better price.
The reason I suggest this strategy is that the appraisal process for a home that is not in escrow may be a bit rosier then the reality of the market. This is no offense to Bugs or other appraisers at all. It is just that I think you can get a better deal if you take your time on it. The caviot would be that if you can just get a SMOKIN deal on the buyout without putting it on the market then maybe take the deal… just realize that even with the buyout, you are purchasing a depreciating asset. Maybe try to for sale by owner it?