I built this from scrap lumber. It's 2x8's and 3/8 inch plywood. Measures 25 x 15 inches.
Commercially plastic ones sell for $30-$40. This should cost about $20 to buy material.
I start most workouts with the box. Low impact good warm up.
I use this more for push ups than anything else. It's not good for the wrists to do flat hand push ups. The bar can also be used as an anchor point for a suspension trainer. Retail $10-50. There are a lot of variations. Basic and simple works fine.
These can be used in place of dumb bells. There are a lot of movements that resistance bands can be used for. This set sells at WM for about $10. Each band has a different resistance, they can be combined in the handles to increase.
I have a video of how I made my own trainer, there are a LOT of variations on youtube. Commercial models range in price form $20 to $200. They all do the same thing, I made mine for less than $10.
This was a home-made slam ball. I went through three in two years. They are fairly cheap to make but adding up three I could buy an actual slam ball. Bought one right around Christmas for $25, it's 20 pounds. I just have to wait and see how long it lasts.
I don't have a slam ball in the program, I just think it's a great workout tool. It gets the whole body involved. Substitute slams for any cardio movement.
My sandbag started life as a small tool bag from Harbor Freight Tools, about $6. I put 18# of sand in zip lock freezer bags in the tool bag.