Ok, I'm getting some mixed messages here from different FAQs and different forums.

Some people insist that getting the Master Sword, (requires 60 DEX, 120 Damage with 10% one-hand bonus) can be gotten in Xardas's old tower in the Valley of Mines.

Other people have said that the Master Sword can ONLY be gotten from Martin, the militia guy who's on the harbor dock selling weapons. (An FAQ on Gamefaqs states this, as the sword was removed from Xardas's old tower in the NOTR version of the game.)

I have seen the master sword in Martin's inventory, but only one time, and I didn't purchase it.

Some people state that it only appears in his inventory ONE time, and then he equips it - and its "gone" forever, sorry about your luck.

Some people state that you can "beat" it from or pickpocket it from him after he equips it.

Does anyone know which is correct?

If anyone has any answers, I'd greatly appreciate it.

After you first look at his goods and leave, he will equip the most valuable weapon he has, which happens to be the Master Sword. One way to deal with this is to get the Orc Slayer from the pyramid and sell it to him. He should then equip that because it's more expensive.

You sir, are brilliant.

Why didn't I think of this?

Well, now that I think of it, it's quality not just cost, so more damage wins I guess.

This is pretty much a necroposting, but as of 2022 this workaround doesn't work.

What works for me to get on with militia quest and everything is to talk to him only about quest stuff, never talk about buying things. That way bug never triggered and you can return to him once you have a lump sum of 2400 to purchase sword.

There is a second sword on the head of thieves guild, however, how you solve her quest will determine whether you get it or not, as only killing her personally (which isn't easy in chapter 1) will yield the sword.