Learn English – Etymology of ‘ends’ or ‘the ends’ and other current British/London slang

Wikipedia gives info on origin and context of both terms:

Nerf (computer gaming):

In video gaming a nerf is a change to a game that reduces the desirability or effectiveness of a particular game element. The term is also used as a verb for the act of making such a change.The opposite of nerf is buff (in one of that term's two usages).

The term originated with Ultima Online, and refers to the Nerf brand of toys which are soft and less likely to cause serious injury.It is used in the context of virtual worlds such as MMORPGs (like UO) and MUDs, but has become a part of the general vocabulary of gamer slang and can be found in various places where adjustment of power levels from one version of a game to the next is relevant.

Buff (computer gaming):

Buff is a term used in some video games, especially MMORPGs and MUDs, to describe increases in the power of a game element. There are two main usages. The first describes a permanent (or at least indefinite) increase in power levels as a result of adjustments to game mechanics, usually in pursuit of game balance. In this usage, buff is the opposite of nerf. The second usage of buff describes an effect (usually cast as a spell) that temporarily enhances a player.

You can read the linked articles for more.

Online Etymology Dictionary has an entry for buff as well:

1570s, buffe leather, from M.Fr. buffle "buffalo" (15c., via It. from L. bufalus; see buffalo). The color term comes from the hue of buffalo hides (later ox hides); association of "hide" and "skin" led c.1600 to in the buff, and use of buff or suede to polish metal led to sense of verb "to polish with a buff" (1885). Related: Buffed; buffing. Buff-colored uniforms of N.Y.C. volunteer firefighters since 1820s led to meaning "enthusiast" (1903).

The Buffs are men and boys whose love of fires, fire-fighting and firemen is a predominant characteristic. [N.Y. "Sun," Feb. 4, 1903]

Adj. meaning "well-built, hunky" is from 1980s, from sense "polish, make attractive."

Chambers Dictionary 11th Ed.:

ORIGIN: Poss *do*llars and ca*sh*

Partridge Dictionary of Slang:

Possibly a combination of dollars and cash; there are also suggestions that the etymology leads back to doss (temporary accommodation), hence, it has been claimed, the money required to doss, or Scottish dialect doss (tobacco pouch, a purse containing something of value) – note, too, that tobacco is related to money via quid. US dosh didn’t survive but in mid-C20 UK and Australia the word was resurrected, or coincidentally recoined US, 1854

Oxford Advanced Learner’s Dictionary 8th Ed.:

1950s: of unknown origin

Oxford English Dictionary:

Origin unknown.

1953 H. Clevely Public Enemy xviii. 114 He hadn't enough dosh on him.