I think consent can be bought, for all sorts of things.
I have friends who used the Adult Work site, to earn extra money, they had no partner, certainly no pimp, they picked and chose the jobs they wanted and had various other conditions as well as payment.
Several of them would not meet a punter for sex without first having done a video call with them - so no matter how much money they were willing to pay, if the sex worker did not like the look of them/did not want to have sex with them for some other reason, the sex would not happen. The others made it clear they could and would refuse the job on the day if they wanted to (and set themselves up so that this was possible).
This doesn't mean that doing this work was good for them - none of them do it now and I am fairly sure they'd all agree it wasn't good for their mental health at all.
Now thats obviously not always the case and the idea that every sex worker is consenting because they're being paid is clearly wrong.
I can think of a few other areas where people may appear to be consenting to something harmful and damaging, but there are other factors that mean that consent isn't really consent.
Children who learn to box and are offered boxing as a way out of an otherwise shitty life for example - are consenting to a high risk of brain damage. Is that really consent, given the options available to them and their level of understanding at the time, I don't think it is, but it is legal and those putting kids in that situation are generally applauded!
Going for a less obvious example - little children who learn gymnastics or ballet - both of these require training that will 100% damage them physical and irreparably if they continue it into adulthood and do it competitively/professionally and probably even if they don't get that far. If they do, most will suffer mental health issues, eating disorders, body dysmorphia, depression etc etc as a result of the training and discipline required and the generally toxic dance/gymnastics industry.
When did a parent last genuinely think about this and consider informed consent when sending their 3 year old to gymnastics or ballet class?
It's really not a simple topic.