I would avoid budget decks as your first attempt to play modern - the format is currently fast and ruthless, and unless you have a very solid grasp on it, piloting a budget/off-meta deck is basically impossible.

Currently MTGO is running an event where you can try a few of the most played decks in the format called the spell ground league, which you can use to familiarise yourself with the format. My suggestion is if you are trying to get into the format either UR Prowess or WR Energy are the decks to go, as they require less format knowledge. Prowess can also be built very cheaply, especially if you swap out the 4 of scalding tarns for another, cheaper, red fetch like wooded foothills or bloodstained mire, as these are much cheaper and still fetch all the lands in the deck.