When the texts refer to pinning up trains, pinning up sleeves, pinning together bodices, &c., they're talking about straight pins, just a plain pin with a small head. Often times a dress was simply pinned together in front or back, or pinned directly to the stays beneath to hold it closed.

There are other, very small brooches (commonly referred to as "lace pins") which were also used, but they were meant to be ornamental. You see them pinning together belts and sashes, pinned on sleeve puffs, pinning lace veils to bonnets, pinning shawls together, &c.

Sleeve puffs are in evidence 1795-1820, so it's difficult to say how long pinning them up continued. There is a very nice muslin habit shirt of Princess Charlotte's in the Museum of London with big puffs on the sleeve heads - this shirt's puffs are achieved with tiny muslin ties on the inside, attached at mid-upper arm and in the shoulder/armscye. When the ties are fastened, it draws up the sleeve. Releasing the ties facilitates laundering and ironing, as would the use of pins.

I frankly do not know exactly how much a paper of pins would have cost; I am guessing that since each pin had to be stamped out by hand and head formed manually that pins were a bit more dear than they are today, i.e., I doubt that a lady could purchase 200 silk pins for the equivalent of a couple dollars.

Hope this helps,

Louisa
Mistress of the Garderobe