Thank you each of you... all of what you wrote helps to know!
Jelly rolls and such always seem like such a tempting way to get a large variety of fabrics from one collection, but so far I've preferred to cut my own too.
I did just find one seller on eBay who actually preshrinks, irons, and rotary cuts the fabric for her precut fabrics:
Twin Orchards Textiles Right now she has mostly color mixes of batiks. So I'm looking at a couple of her auctions and if I buy one it will be a good way to find how accurate her cutting is.
Those Moda collections are sorely tempting too.