1883 Morgan rated MS
the Morgan had a price tag of $50 which he sold me for $40
I have an 1883 Morgan, New Orleans ("O") mint, in uncirculated condition that I bought on eBay last year for $43 + $2.00 shipping & handling.
I also have an 1884 O Morgan (uncirculated condition) that I bought on eBay for $46 + $2.50 S&H.
On the other hand, I bought an 1883 Morgan in VF condition for $34 + $0 S&H, so.....
, based on eBay auctions, that "O" minted coins are a little more collectible and therefore a little higher priced.
So I believe you did just fine on the Morgan. You definitely did not get hosed on it.
I don't know about the other coins you referenced.