Glen and Diane Okumura (both age 48) are married, file a joint return, and live at 39 Kaloa Street, Honolulu, HI 96815. Glen's Social Security number is 111-11-1111, and Diane's is 123-45-6789. The Okumuras have two dependent children, Amy (age 15) and John (age 9). Amy's Social Security number is 123-45-6788, and John's Social Security number is 123-45-6787. Glen works for the Hawaii Public Works Department, and Diane works in a retail dress shop. Glen's employer provided medical insurance to Glen and his family during 2016. The Okumuras had the following transactions during 2016:

1. Glen earned $57,000 in wages and had Federal income tax withholding of $2,000.

2. Diane earned $38,000 in wages from the dress shop and had Federal income tax withholding of $1,000.

3. The Okumuras sold a small apartment building for $89,980 on November 15, 2016. The building was acquired in October 2010 for $200,000; cost recovery was $66,820.

4. The Okumuras received $3,000 in qualified dividends on various domestic corporation stocks that they own.

5. The Okumuras sold stock on November 5 for a $23,000 long-term capital gain and other stock on December 10 at a $2,000 short-term capital loss.

6. The Okumuras had the following itemized deductions: $12,895 unreimbursed medical expenses, $10,500 personal use real property taxes, $7,000 qualified residence interest, $1,500 of Glen's unreimbursed employee business expenses, $535 of investment-related expenses, $2,700 of state income taxes paid, and $1,061 of sales taxes from the sales tax table.

7. The Okumuras spent $3,000 on qualifying child care expenses during the year.

Compute the Okumuras' 2016 net tax payable or refund due. Also write a letter to the Okumuras, describing how the sale of the apartment building affects their return.