This is a budget deck upgrade for Avalanche!, the Simic/Quandrix (U/G) Starter deck on MTG Arena unlocked through the Color Challenge.

This Deck Upgrade costs: 1 Common WC's || 17 Uncommon WC's || 0 Rare & Mythic WC's
All other cards in the deck, including the rares and mythics, are obtained for free from the other Arena Starter Decks.

The Avalanche! preconstructed deck is built around two main themes: Snow and Ramp. This upgraded list focuses more on the Snow synergy. If you're looking for an upgraded ramp version, check this one out.

CREATURES 

Frost Augur is one of our strongest snow pay-offs. A 1 mana 1/2 isn't very remarkable, but one that can draw you a card each turn for only 1 mana can be very powerful. The catch is that it's effect only works if the top card of your library is a snow card, so for this reason we want to run as much Snow as possible. Sculptor of Winter is a Snow Creature, and it helps to ramp us by untapping a target Snow land. Boreal Outrider is a 3/2 body for 3 which is unremarkable, but it's a Snow Creature and it gives our other creatures a +1/+1 counter if they are cast with Snow Mana being used to pay for one of the spell's colors. Spirit of the Aldergard is one of our stronger snow pay-offs. It's body can become a huge threat very quickly due to its power scaling with the number of snow permanents we control, and on top of that it lets us search our library for a snow card and put it into our hand. Thanks to this ability, we are able to comfortably play a non-simic card, Narfi, Betrayer King. For 3UB Narfi is one of our best pay-offs for Snow. He pumps all our other snow creatuers and can return himself to the battelfield from the graveyard untapped at instant speed for only 3 snow mana. 

SPELLS

Blizzard Brawl is an exceptionally powerful fight spell in decks that have snow and good creatures with which to fight. No-brainer inclusion as a pay-off for our strategy. Emergent Sequence can function as both a decent ramp spell and an okay body, much like our Sculptor of Winter. Since our lands are snow cards Emergent Sequence will also get +1/+1 from Narfi, Betrayer King while they are both on the battlefield. So both of our ramp options can become decent 3/3 bodies with the right set-up. Decisive Denial is a good way of filling a couple different roles in our deck depending on the match-up. Against aggressive decks we will most likely be using Denial as an extra form of removal, but it can also double as a subpar counterspell against control decks. In a Standard BO1 environment, that's not a bad deal. 

CONCLUSION

I hope you enjoy this deck and that it serves you well. There's a deck tech video on youtube attached to this guide and I stream on Twitch here so don't hesitate to reach out :) I'd love to hear your experience with the deck. Good luck and have fun!