Yes, a lot of wealth was tied up in land. But a lot of riches didn't exist for people except on paper as well. Merchants would tote around ledger books with their account balances and get a lot of trade conducted without hard currency in their pockets at all. Some of that could occur with D&D parties as well. They sell the sword, credits in ledgers would be switched from one person to the other, and the actual cash would still sit wherever it has been sitting for years as its value has been transferred from ledger to ledger.
