While TCGplayer prices update quickly because so many players and vendors are selling cards on the site (which means someone likely has a copy to list), ChannelFireball and Card Kingdom don't typically update their prices while a card is out of stock
A 6/6 with vigilance, however, is great
The best modes are likely going to be searching for two lands and distributing two +1/+1 tokens on each creature you control
Because it reads your linked collection, Augur can recommend upgrades you already own, suggest cards within your budget, and add, remove, or swap printings just by asking
Weve seen this on vehicles before, but for the same mana value, this will be easier to get going than Hoard Hauler (just with the downside of it being a one-shot effect)