> If you make that pen available to me under these conditions? Sure.
Let's leave aside whether the law (in whatever country) permits such a one-sided contract, and ask - should it permit it? There are plenty of contract terms that are illegal (i.e. not backed by law), such as usury [1] or various anti-competitive practices, because their enforcement is seen as either unfair, or a detriment to society, regardless of whether they were entered freely. Contracts are not and should not be above the law.