@DABU
I don’t believe you can use an annual exchange rate. At least, the income from the sale should be recognized at the exchange rate on the date of the sale. If you are not convinced, I will try and find the actual regulation for you. @pk may also have experience here.
Allowable additions to your cost basis are listed on page 8 of IRS publication 523.
https://www.irs.gov/pub/irs-pdf/p523.pdf
Improvements are always allowed, as are the broker’s commission. Note that an improvement is something that is attached to the real property — the land itself or the buildings attached to the land — and must either increase the value of the property or make the property better, or extend the property‘s useful lifespan. Since a perimeter fence is attached to the real property, that is include a bowl. I don’t believe you can include your travel expenses. Some of the government transaction fees and taxes are probably allowable, but you should refer to publication 523.
