Price should be `double` instead of `num`

[ciriousjoker]

Why would you use num in Dart? I haven't encountered a case where using num made practical sense, but it especially doesn't make sense when the thing you have is already a floating point number, aka a double.

By returning num, when using the price you have to convert it back to a double even though it already is one.

[ciriousjoker]

Keep in mind this is super low priority since you can just call .toDouble(), I was just wondering why that decision was made in the first place.

However, please don't waste resources on this until the crashes are fixed...