You can own it, you can use it, but you can't buy it ever...so it's all good. Brilliant.
Of course you can buy it. You just don't have any special "right" to, any more than you have the right to buy a car or a big screen TV. Get it now?
You can have legal representation, but there is no right to hire a lawyer.
You can have freedom of religion, but there is no right to go to a church.
You can have freedom of the press, but there is no right to buy paper and pencil.
You can have freedom to petition government for redress of grievances, but there is no right to contact your congressmen.
You can have freedom to not incriminate yourself, but there is no right to keep quiet.
Any other rights you like to technically allow, but restrict in reality?