NOTE
====
The list below is of weapon magic properties that do not require attunement (common, uncommon, and rare 
- there is no very rare), so you could, with DM permission, purchase and add them to a weapon you already have.

Also with DM permission, you might be allowed to do variations of these abilities.
For example:
- Slayer ability 	- choose a different creature type other than dragon or giant
- Smiting ability 	- choose a different creature type other than construct to increase hit/damage from +1 to +3
			- choose a different creature type other than construct to do 4d6 on a natural 20
- Lightbringer		- choose a different creature type and/or damage type
- Waterborne		- choose a different sub-skill check to get advantage on.
			  such as Leap on Athletics (jumping) or Climb on Athletics (climbing)

Not listed below, but some wondrous item abilities with no attunement could be added to a weapon with DM permission.

Just some thoughts/ideas to play with and how to spend any extra cash weighing down your pockets.

RARE (+500 GP)
==============
Dragon Slayer (rare ability)
	When you hit a dragon with this weapon, the dragon takes an extra 3d6 damage. 
	For the purpose of this weapon, "dragon" refers to any creature with the dragon type, 
	including dragon turtles and wyverns.


Giant Slayer (rare ability)
	When you hit a giant with it, the giant takes an extra 2d6 damage of the weapon's type 
	and must succeed on a DC 15 Strength saving throw or fall prone. 
	For the purpose of this weapon, "giant" refers to any creature with the giant type, 
	including ettins and trolls.


Vicious Weapon (rare ability)
	When you roll a 20 on your attack roll with this magic weapon, 
	the target takes an extra 7 (2d6) damage of the weapon’s type.


Weapon of Smiting - Bludgeon only (rare ability x2 - bought seperately)
(1)	You gain a +1 bonus to attack and damage rolls made with this magic weapon. 
	The bonus increases to +3 when you use the weapon to attack a construct.
(2)	When you roll a 20 on an attack roll made with this weapon, the target takes 
	an extra 7 (2d6) bludgeoning damage, or 14 (4d6) bludgeoning damage if it's a construct. 
	If a construct has 25 hit points or fewer after taking this damage, it is destroyed.


Weapon of Venom - Piercing/Slashing only (rare ability)
	You can use an action to cause thick, black poison to coat the blade. 
	The poison remains for 1 minute or until an attack using this weapon hits a creature. 
	That creature must succeed on a DC 15 Constitution saving throw or take 2d10 poison damage 
	and become poisoned for 1 minute. 
	The weapon can't be used this way again until the next dawn.


UNCOMMON (+100 GP)
==================

Hew (uncommon ability)
	Deals maximum damage when the wielder hits a plant creature or an object made of wood. 


Lightbringer (uncommon ability)
	Deals an extra 1d6 radiant damage to undead creatures.



COMMON (+50 GP)
===============

Beacon (common ability)
	The bearer can use a bonus action to cause the item to shed bright light in a 10-foot radius 
	and dim light for an additional 10 feet, or to extinguish the light.

Celestial (common ability)
	The weapon is half the normal weight and inscribed with feathered wings, suns, and other symbols of good. 
	Fiends find the item's presence repulsive.

Compass (common ability)
	The wielder can use an action to learn which way is north.

Delver (common ability)
	While underground, the bearer of this item always knows the item's depth below the surface
	and the direction to the nearest staircase, ramp, or other path leading upward.

Dragon (common ability)
	This item is made from scales and talons shed by a dragon. 
	Perhaps it in corporates precious metals and gems from the dragon's hoard. 
	It grows slightly warm when within 120 feet of a dragon.

Elf (common ability)
	The item is half the normal weight. 
	It is adorned with symbols of nature: leaves, vines, stars, and the like.

Fey (common ability)
	The item is exquisitely crafted from the finest materials 
	and glows with a pale radiance in moonlight, shedding dim light in a 5-foot radius.
	Any metal in the item is silver or mithral, rather than iron or steel.

Fiend (common ability)
	The item is made of black iron or horn inscribed with runes, and any cloth or leather
	components are crafted from the hide of fiends. 
	It is warm to the touch and features leering faces or vile runes engraved on its surface. 
  	Celestials find the item's presence repulsive.

Gleaming (common ability)
	This item never gets dirty.

Guardian (common ability)
	The item whispers warnings to its bearer, granting a +2 bonus to initiative 
	if the bearer isn't incapacitated.

Illusion (common ability)
	The item is imbued with illusion magic, allowing its bearer to alter the item's appearance 
	in minor ways. Such alterations don't change how the item is worn, carried, or wielded, 
	and they have no effect on its other magical properties. 
	For example, the wearer could make a red robe appear blue, 
	or make a gold ring look like it's made of ivory. 
	The item reverts to its true appearance when no one is carrying or wearing it.

Language (common ability)
	The bearer can speak and understand a language of the DM 's choice 
	while the item is on the bearer's person.

Moon-Touched Sword (common ability)
	In darkness, the unsheathed blade of this sword sheds moonlight, 
	creating bright light in a 15-foot radius and dim light for an additional 15 feet.

Sentinel (common ability)
	Choose a kind of creature that is an enemy of the item's creator. 
	This item glows faintly when such creatures are within 120 feet of it.

Temperate (common ability)
	The bearer suffers no harm in temperatures as cold as -20 degrees Fahrenheit 
	or as warm as 120 degrees Fahrenheit.

Unbreakable (common ability)
	The item can't be broken. Special means must be used to destroy it.

War Leader (common ability)
	The bearer can use an action to cause his or her voice to carry clearly 
	for up to 300 feet until the end of the bearer's next turn.

Waterborne (common ability)
	This item floats on water and other liquids. 
	Its bearer has advantage on Strength (Athletics) checks to swim.