Barnes & Nobles online currently has a selection of older LEGO sets discounted by 50% off. You can see the full list of sets on sale here. Spend $35 or more and your order qualifies for free shipping to US destinations.
Most items are currently instock, but if they are out of stock, you can choose in-store pickup and see which store have the sets. Barnes & Nobles is a US retailer that charges in USD prices and ships worldwide.