Most of what typical stores sell as cashmere is not what would classically have been called cashmere. It is fiber from the same animal but not the underlayers that are really soft. So "cheap priced cashmere sweater with decent quality" is really an oxymoron at the conventional retail level. The cheap stuff is not real cashmere. I mean, when places like Old Navy sell cashmere at ridiculously low prices then you should know it will not be the same quality material.
If you want to know what the material feels like then go to a few stores and compare fabrics at different price points. Alternatively, get a cashmere scarf or a pair of gloves from a good maker and compare that against the department-store level cashmere.
If you really want a cheaper product that performs similarly to cashmere, then I recommend alpaca. It has similar thermal performance to cashmere but is generally not quite as soft (still much nicer than wool though). There is a lot of production from Peru and Bolvia so you can find it at quite reasonable prices. There are makers selling hand-woven alpaca sweaters directly on ebay for $30-$50.
Hm, okay. I am looking at a Snow Lotus sweater, after recommendations from you, on ebay for $100, and I am waiting for measurements. If the measurements are what I am looking for, I will buy it.