So I, for one, see a whole lot of flaws with the concept of prison that is used in the book / show, though I do think it was intentionally made to be flawed in the series so that fits.
What isn’t touched on a lot is that when a sleeve of a convicted criminal is put into cold storage loved ones / friends/ family, whoever, has the opportunity to ‘rent’ the sleeve and thereby keeping it on ice so that no one can use it, risking damage or death before the convict’s stack sentence is up. Much like renting a car, etc., or a pay to own deal, if you miss a payment or are late on a payment there is a high chance that you’re out of luck and the sleeve will be put into circulation for renting.
I do believe that the price for renting is based on the severity of the crime as well as a general estimate of what that sleeve would be worth to someone. Ryker, for example, would be on the more expensive side. While he doesn’t have things like ‘gecko hands’ and other things that we see in elite designed sleeves later on, he does have a very physically fit, capable, and attractive body, he has military grade combat wiring, software/hardware in his nervous, musculature and other systems, and has a great deal of actual combat experience so all in all would go for somewhere on the higher end.
Ortega had been paying the mortgage on Ryker’s body, but when Bancroft swept in with his much higher bid / purchase, Ryker was released to him instead, despite the active ‘mortgage’ that Ortega had.
The legality of all of this is never really explained, but this is one of the major flaws that exists in this penal system: as we see a lot in our own current world, if you have enough money, the rules don’t always apply.