To put what the CPA said in lay terms:
You only have to pay taxes on the portion of your sale that is "profit". If you paid more for your
DVC than you sold it for, then you won't owe taxes. If sold your DVC for more than you paid for it, then you will owe taxes on only the amount that exceeds your purchase price.
To calculate it:
Look on your purchase contract. Find the purchase price, it should also list out all the fees and closing costs you paid on the purchase of the contract. You can not include any interest from a loan you might have taken out to purchase your DVC, but you can add any loan origination fees, closing costs, etc. Take all those costs and add them up. This is what your DVC has cost you.
Then take the amount on your 1099, subtract off any sales commissions, fees, etc. that you paid in direct relation to the sale of your DVC. This is your net sale price.
If your total DVC purchase cost is higher than your net sale price then you won't owe any taxes. Just make sure you fill out the proper tax forms so you can show this to the IRS.
If your total DVC purchase cost is lower than your net sale price, then subtract your DVC purchase cost from your net sale price and this is your taxable portion of the sale. You will have to pay income tax on this amount.
Disclaimer: I am not a CPA and this is not tax advice. Consultation with a tax professional is advised.