When accounting for the disposition of the asset on your taxes, you claim the depreciation as 20K (the amount you should have, but did not originally take), and at the same time claim 10K as an expense on Schedule E, so that your overall losses on the property truly match the amount of depreciation being assessed against the property.  

Regarding fees, there are three buckets of fees that investors should be aware of. 1) Upfront Fees - these include but are not limited to acquisition fees paid to the DST sponsor/syndicator, commissions paid to the broker/advisor representing the investor, and other marketing costs associated with packaging and marketing the DST investment 2) Operating Fees - property management fees, asset management fees, and fees paid to the master tenant 3) Disposition Fees - the brokerage fee paid to the sponsor when the property is sold. 

Tax codes cover business operations, income and expenses, tenancy, ownership and the disposition of assets by sales.

They’re disposition specialists and help tons of wholesalers in their markets get their deals sold.

The way we do our disposition is through a highest and best auction/bidding war on the contract, so assuming the realtor brings the cash buyer should we factor their commission into our calculations?

If you believe that you can establish to the satisfaction of the IRS that tax avoidance was not a principal purpose of both the exchange and the disposition, then go for it.

If, however, the real property is depreciable property (e.g. property that earned rental income and on which you declared capital cost allowance), then the required withholding would be 50% of the gross sales price.REDUCING WITHHOLDING TAX You may request to have the non-resident tax withheld on the net capital gain on the disposition instead of the gross sales price This requires filing the appropriate forms with the CRA and also obtaining a Certificate of Compliance.

The first question to answer is whether or not your grandmother had a will and whether the will designates the disposition of the property.  

The old depreciation of the actual property is not changed unless you do partial disposition of your property. 

Make it easier on yourself by having a legally binding plan for the disposition of assets.