These are all (except for coin C) early Vietnamese cash-style coins. They are denominated in "phan" - sometimes spelled "van". Vietnamese cash are made of a high-lead brass.
A: 1 phan from emperor Gia Long, who ruled from 1802 to 1820.
B: I can't quite read the emperor's name on this one, but it's definitely Vietnamese, a 10 phan. best guess is emperor Duy Tan (1907-1916).
C: This is the older Chinese coin. It's a 2-cash coin from emperor Shen Zong of the Song dynasty, cast during his Xi Ning period (1068-1078 AD). Despite being so old, it's still relatively common, only listed at a few dollars in my Chinese Cash catalogue. While the mediaeval Vietnamese did make "trade copies" of Chinese cash coins, this coin is nice enough, and of a distinctly different colour to the rest of your coins, that I would assume it's a genuine Chinese cash. To make it "right way up", rotate the pic 90 degrees anticlockwise.
D: 1 phan, emperor Minh Mang (1820-1840).
E: this one definitely is what I think coin #B might be: 10 phan, Duy Tan. The reverse side is shown upside-down.
F: 1 phan, emperor Tu Duc (1848-1883). The pic is upside-down.
G: 10 phan, emperor Thanh Thai (1889-1907). The bottom pic is upside-down.
H: 1 phan, emperor Thieu Tri (1841-1847). The pic is upside-down.
I: identical to coin #H only clearer, which helped me realize I was looking at these two coins upside-down!

J: um, it's the same coin as the one pictured as coin A, right down to the little red spot on the left inner rim and the corroded red patch on the reverse. Did you mean to take a pic of a different coin, or were you just testing us?

As for value, most Vietnamese cash coins are fairly cheap and common; they
find entire pot-fulls of coins fused together on a regular basis. There's a fellow at my coin club that visits Vietnam regularly; he sells his "spares" for 2 or 3 dollars each.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis