Only when you get the third Bird will you feel like you're really doing something worth the mana
Our options are therefore as follows: Azorius v Jund: Will, Scion of Peace & Ikra Shidiqi, the Usurper + Kediss, Emberclaw Familiar Rakdos v Bant: Judith, Carnage Connoisseur & Shanna, Purifying Blade Selesnya v Grixis: Trelasarra, Moon Dancer & Solkanar the Swamp King Boros v Sultai: Firesong and Sunspeaker & Zimone and Dina Golgari v Jeskai: Beledros Witherbloom & The Archimandrite Okay, there should be six, but if you can find an oppositional pair in Dimir and Naya that can both be reasonably called a life gain deck, go for it
Take your pick of the dozens of options
Most of the buy it nows and obos (or best offer) are listed in the $450-550 range
Once it dies, you'll likely be drawing more than one card, more than replacing what you lost in terms of resources