Here's a thought experiment: Imagine that you are born as any random person in a society. You could be born as a white male of exceptional intelligence with 1% rich parents, or you could be born as a girl of a minority race to junkie parents and suffer from mental health issues your entire life. Now, without knowing what kind of person you're born as, design a just society in terms of, say, the level of income redistribution, tax-provided health care, or whatnot.
Getting back to your original question of whether somebody should pay more for a laptop than somebody else; well, IF you accept (some amount of) income redistribution, it's more of a technical question how to implement it. I imagine it'd be easier to implement with income redistribution, social spending on low-income citizens or whatnot rather than having wealth- or income-dependent prices on everything.