Happy Easter

[WiltonRanch]

If you have the livestock, that progression would definitely be the cheapest way to do it. Push it, pile it, and let the cows graze around the piles and stumps and stump holes and roots. Wait 20 or 30 years till the roots and the brush piles are rotted down, then turn it into farmland. Not sure how many decades it would take for the big stumps to ever rot though.
As an added bonus, you don't lose so many nutrients and organic matter to burning it.

I like that idea. Father posthumously left me some unfinished brushing to clean up. I like the idea of throwing some oats at it and disking them in for the cows to eat. Severe hilly terrain.

[Taiga]

I would say closer to $2500/ac today to have land cleared and made ready to farm.
Yeah those big willow root balls are something else.

[blackpowder]

BIL had fire go through their pasture. Where the willows were it burned out the roots. Ground sunk a few feet from that. Fought fire for atleast part of every day for almost a month. Roots would be burning and a wind would cause flare-ups.

That explains certain ancient burn patches found in soil profiles I've cleared.