So I would like GOG to be avaible in spanish and that you can buy games in mexican and colombian pesos

This has been proposed before. I would love to have the GOG website in Spanish, if only so I could recommend it to people who won't be too comfortable purchasing online in a website in another language. But it is a big investment (especially if they also offer customer support in Spanish), so they would have to factor all the pros and cons.

As for the pesos, they add support for new currencies every once in a while, but I don't know the intricacies of the decision-making.

Can they at least add boacompra payment method ?