I had already purchased the 'Large Tortoise Shell Shield' before starting any missions. I had it equipped before the 'Armor' Mission even started and I said 'armor' to determine the details. I got the description of the "shell shield" but then Gendo gave me 30 ryo. For just saying 'armor' while having the shell shield equipped. I only have one shield. I tried saying 'armor' again and the same thing happened, got another 30 ryo. I took off the shield and said 'armor' and Gendo basically said 'give it to me' and got NO ryo for it. I then gave the shield to him, and got no ryo for it.
Now for the 'Weapon' Mission, if you say 'weapon' over and over then you will get 4 ryo over and over, not as bad as 30, but it is still there.