I took a look at the financial filings for the election, and here are some interesting figures for all campaign contributions and spending from 11 November 2015 to 5 June 2016:

PPK raised $3,794,990.54 and spent $3,322,546.75 throughout the whole campaign.
Keiko raised $4,599,953.38 and spent $4,626,363.16 throughout the whole campaign.

PPK raised $1,352,169.55 and spent $1,657,670.39 during the second round alone.
Keiko raised $585,686.57 and spent $1,329,500.55 during the second round alone.

If all races from both rounds are counted, the total money raised is $19,786,431.52 and the total money spent is $18,949,825.60 throughout the whole campaign.

I have a feeling these figures pale in comparison with American campaign contributions and spending.

(All figures in US Dollars. Campaining involves both presidential and congressional races. The second round was held between April 11 and June 5.)