The cost price of obtaining drugs to sell on the inside may be low to the inmate for the reasons QtM outlines but the base cost of drugs isn’t high outside either; they ain’t exactly made from gold dust and caviar. Like many things I suspect most of the price is markup.
A key reason for drugs being expensive on the outside will simply be that it’s what the market will bear. And on the inside, the market probably won’t bear as much. Same way an item will cost less in a poor neighbourhood than in a rich neighbourhood.
Others above have said “why would dealers sell to inmates inside if prices are lower if they can sell to people outside where prices are higher?” As long as the price that can be obtained on the inside is higher than cost, there is profit in it. And the only reason you wouldn’t seek to make that profit would be if you could sell your whole inventory at high prices on the outside. But that may well not be the case. And a prison is a concentrated group of drug users.
Huge amounts of retailing effort goes into market differentiation; selling the same thing at a low price to people who can only afford cheap, and at a higher price to people who can afford more.
It really depends on what is being meant by ‘drugs’ being cheaper.
Drugs can be in almost any concentration, the effect can vary completely differently too.
Drugs in prison are typically cut much more than on the street, however the prison user may well feel a greater effect because they do not have the tolerance of more concentrated doses that the street user may well have.
In other words, prisoners get more of an effect from lower purity drugs because they simply do not take as much or as strong doses.
So how do you weigh up the cost of drugs? do you look at how much per dose, do you factor in purity? or perhaps do you, as a user, decide the value based upon the effects.
Prisoners are not that bothered about the strength of a drug, what they want is the effect, if they are off their faces then as far as they are concerned it is good value, its not about volume, or strength.
Maximum effect for minimum cost.
When prisoners are released, it is well known that they are at greatest risk of death from overdose in those first few weeks post release, because now they start taking stuff that they cannot handle, they just do not have the tolerance or resistance of the street user.
If you wanted to do a true comparison of drug prices inside and outside prison, you would have to look at drug quality and also quantity per dose.
My bet is that you will find that drugs in prison are at least 3-4 times more than on the street for similar amounts of the effective agent, but I doubt very much that like for like comparisons are being made here.