In my opinion this is an easy doable suggestion so hope i wont bore the staff reading this.
1)Make PokeMMO donation cheaper when player buy more.
e.g.
$10 = 1000
$20 = 2200 (bonus 10%)
$30 = 3450 (bonus 15%)
$40 = 4800 (bonus 20%)
Something along those lines. This way, Pokemmo would get more people donating higher amount since they get the bonus points and aswell as making it cheaper for some people who often donate.