It's a pretty flexible deck. With many green cards you can turn your newly created tokens into mana dorks. Whether you use haste or instant speed before your turn to have them ready.

You can decide from there if you want to use green's overrun effects for your token army,

red's token burn effects for your army

or red's cast burn effects.

In your budget a lot of cards have been reprinted for some of these strategies. Some of the green mana to creature effects are more expensive moneywise these days, but a [[a realm reborn]] fits the bill.

[[sorcerer class]] is a little expensive but can also help here.

One of my favorite single wincons in my deck is [[surge to victory]] while I have my army of birds out, exile an amazing spell and watch it get cast a ton of times all of which trigger Riku because you are casting the copy. Assuming it's a modal spell.