Agreed, 25c is too small, min should be $1. Also I think the sweet spot is between $1-6, IMO there should be multiple options in the middle here.

Yeah, the current pricing jumps from $1 to $12 a month, $1 to $4 is $4-$24, quite a gap. Honestly, I'd also prefer monthly contributions, thinking in week increments is an american thing. Credit card statements and salaries come in monthly for most of the world, I think.