R202 'Lost and Found' shop includes a number of zero credits blank entries (weapons section). When I bought one it showed me as having replaced a gun turret with a cargo bay? It doesn't actually do anything though.
Save game file:
R202 Pirates keep dropping all their stuff
Land on the pirate planet, there are heaps of items and credit chips everywhere. If you launch and land again a new lot (usually?) generates.
Save game file: