I would need to deduct $4001K from my structure sales price?
yes, you've got it.
Would I them leave the selling expenses for the appliances blank?
yes, you can leave those blank. You only need to spread your sales expenses across the land and the structure. Your sales expenses on an asset, are subtracted from your gain on that asset. So with a $1 gain on the appliance, if you allocate any sales expense to that asset, you'll have a loss on that asset. That will skew the depreciation recapture then. Showing a loss on some assets and a gain on others will tend to skew things a bit. I don't know if such a "skew" would attract unwanted attention from the IRS or not. So it's best to avoid it.
The important thing is to have depreciation correctly recaptured. If you show a loss on on asset, then some to none of that depreciation will be recaptured and taxed as ordinary income. Instead, it gets included in your gain and taxed at the capital gain tax rate.
For most, there's not that much difference in the tax liability between the two tax rates. But depending on your gain and your overall AGI, it can have at least quite a noticeable impact.
