Yes 5,226 is very poor exchange rate. I just came back from Colombia. The best rates are withdraw money from ATM's which located inside bank branches ,shopping malls or dedicate stores and have opening time limits, there is a max limit 300 to 600k but at the airport up to 1500K. Cash isn't good idea because mony exchangers are not so common there and their rates usually very poor, if you are bringing cash US Dollars are most preferable.