I use large horse troughs and or those large wooden shipping crates you can pick up at any pallet place.
I buy feed at Big R and when they load it I stand in storeroom doorway and gawk at everything. Noticed they had Huge cardboard boxes that hold sacks of potatoes and pumpkins. I asked and got them free.
They make excellent brooder boxes and if you need larger just cut bottoms off and open one side and join 2 together.. I have a full basement with plenty of room...
I had a big(ish) dog crate that I used for a brooder. I lined it with cardboard to keep out drafts when the chicks were little and added some roosts at various heights and a screen over the top as they got bigger. Around two or three weeks of age I started transferring them to larger runs during parts of the day. I had a 7'X3' run made of poultry netting and PVD pipe that sat on a sheet of linoleum in my garage and I had a little 2.5'X5' puppy play pen that I'd set up outside on days where I could keep an eye on them. Both set-ups I had to cover with poultry netting or screen to keep them from flying out and to keep at least casual predators from getting in. At night I transferred them back into the brooder where they settled in for the night. This worked very well for me since I didn't have their coop ready for them until they were about 6 weeks old.
We made a 4x4 wooden box, about 18 inches tall with half solid, fixed roof and the other half is a hinged screen, and a solid floor. Has a perch across the back and a rail to hang the lamp, and we put it on casters so it's easier to move (since it weighs a bunch). Our first flock this year was raised in a sheep water tank though (which they managed to escape from after a couple of weeks). Thus, the new box.
ETA: Our entire expense was about $20 for the casters as everything else was leftovers from a home addition. I'm currently building a chicken tractor out of even more scrap lumber. Gotta be frugal!
I'm using a dog crate that I sat inside of a Christmas Tree Bag
Being frugal and use what I have - LOL! BUT, it works like a charm. I can pull it up over the dog crate and it keeps pine chips from being scattered all over the place. Then I pick it all up, take them outside to clean everything out and they can munch on bugs and grass through the bottom as I'm cleaning. Put them back and haul them in the mudroom! Amazing what you can do with just things you have around the house!
My 3 day olds are in a Mail sorting box (there are only 2) and it's snug and warm and gives them room to move about, at least for the next couple of days, they are growing very fast