A thousand times yes to the <select> comment. A numeric text field would be much better and faster:

<input type="number" name="someName" />

There is an option to change currency on the top left corner of the homepage (which also changed the temperature to celsius).

The app already asked for my location, which I granted it. Rather than make every user fix the incorrect currency, the app should pick the correct one matching the location and let them override it if they need to.

Great work, congrats. I'd like to calculate the budget for 2 ppl and have temps in C°