What would I buy with a thousand bucks?
I would buy a large rain barrel from Lowes. The 600-gallon one. Since I live in southwestern Washington State and we measure rainfall by the foot, getting water isn’t the problem. It is moving it that can be a bear, as we live on a ridge 1000 feet above the Columiba River.
Take care in how you plumb the thing.
Water off a shingle roof = not potable due to petroleum ingredients in the shingles.
Research filtration methods of catch water before using as other than gray water.