Well...
I can honestly say it takes more than you wood think. We've been in the reclaimed lumber market for a long time.
When we started many years ago i was busting 2 x with a skill saw and straight lining on my table saw with sled. Then to the shapers. It was crude but i got paid.
Best advise i can offer is go slow and steady. Watch the auctions good machines always on the block for fraction of the cost of new.
These days we are running 2 vertical resaws a stenner and griggio, woodmizer Lt40, 42" circular mill, a nyle kiln set up in a 24' container, Diehl SLR, whirlwind upcut, wadkin moulder, 20" and 24" surface planer, 2 head 36" wide belt, several shapers with power feeds, fork lifts, trailers, trucks, dust collectors, phase convertors, banding and strapping machines....
The list goes on and on and to this day i still am aspiring for a few things like an end matcher and oil pre finishing line.
In the barn wood biz you cant always rely on the next truck to have what you need or expect, your best bet is to have a large inventory to cover your ass.
Most important...Dependable talented staff
to run and maintain all these machines.
Good Luck.....