Anyone know if it's possible to buy 'scrap slots' of ads on X or any other social or internet media?

There are some things that would be willing to get into X ads or even tumbler or similar in areas that mainstream ad cos might deem brand unsafe..

I am guessing these ad slots could be bought at 1/10th the regular cost and even give some options like demographics, over 18, certain cities, etc.

Make the slots available with a disclaimer your ad may appear by anti-this and anti-that and cancelled / hate / porn - check box to continue..

I suppose it could start to auction and raise price one day - but for now just put ads in a line.

asking for a friend.