From: http://tappedout.net/mtg-decks/100-infect/

$100 budget version of one of modern's most played deck.

Sideboard is not included because it is entirely dependent on your meta and should be worked on in collaboration with others.

Key things to note about Infect:

The deck wants to load up one creature with a ton of pump spells to swing hard. Add the best pump spells for the cheapest amount that you can.

The deck is fairly cheap outside of the manabase. You can make it cheaper if you play mono green infect; however, blue adds unblockable and control in sideboard so it is often worth running.

Spellskite ruins all the fun. Whilst I don't promote sideboards, the best hate card against Spellskite is Twisted Image and will have to be in the sideboard.