The 1982 £99 zx spectrum would cost £340 (almost $500) in today's money, when accounting for inflation[1] - well within the price range of "conventional" budget PCs.
I can assure you that in 1982, I would have a had better chance of getting my Dad to buy me a Sinclair than my nephew would have of getting his dad to buy him something costing 3.43 times as much.
[edit] Why when all the other prices have come down in computers do people insist everything's fine because of inflation with the removal of the sub-$200 category when Microsoft and Intel did the most damage to that category.