UK, 1805 - 1815 : Cost of Wollaston's Platinum

1800: 1 Troy Ounce platina (Initial Cost, 76% ore)  = £ 0.1334 
1805: 1 Ozt. platina (Cost, at purity)  = £ 0.1749 
1805: 1 Ozt. Platinum (First Base Price)  = £ 0.6525  (USD$ )
1805: 1 Ozt. Platinum (manufactured, retail)  = £ 0.75 - 0.90 (USD$ 3.26 - 3.92)

1805: 1 Ozt. Pt (UK Refiner Cost)  ~ £ 0.4776  (9s 6.5d.)

1806: 1 Ozt. platina (London price, retail)  = £ 0.25  (USD$ 1.09)

Chaldecott noted the cost of flattening an ingot in 1816 was £ 0.15.

Alternately, it's reasonable to presume that variations in Wollaston's bulk costs were determined by Specific Gravity (Pt = 20) of different lots. That is, he offered a Flat Rate (denominated in Silver Dollars per Ozt.) and respective orders were filled and charged accordingly.

402.7825 Libras (=5,959 Ozt) £ 795.  = $ 3,398.28, but where Wollaston could only extract 46% Pt from the platina ore, the Base Cost rises dramatically:

£ 0.1334 *46% + £ 0.20 = £ 0.49 (~ 9 s. 10 d.)

Wollaston's sales to Cary in 1805 indicate 5 crucibles at 1.45 ozt, 1.275 ozt, 2.25 ozt, 2 @ 2.875 ozt with 5 covers (2.825 ozt, so 0.565 ozt ea.) and a larger crucible & cover 4.025 ozt. also 6 covers (3.231 ozt, so 0.5385 ea.) w/ Cary's 10% commission, @ £ 0.875 per ozt.

1805: 1 Ozt. Platinum (Mfg Whol.) = £ 0.7875 
1805: 1 Ozt. Platinum (Mfg Ret.)  ~ £ 0.90

Factoring Cary's 10%, the Producer's First Base Price for ingot is £ 0.6525, 13s.

Citation: The Philosophical magazine: comprehending the various branches of ..., Volume 21 (1806), p.287

Mentioning costs of an experiment in 1806:

 

Chaldecott (1979) is in error; Cary's marketing of Wollaston Platinum was made in April 1805, not 1810. See The Philosophical Magazine, Vol. 21, No. 83 (April 1805) p.297.

[Citation: Platinum Metals Rev., 1979, 23, (3) p.117]
No evidence has come to light of any announcement concerning the intended marketing of Wollaston’s malleable platinum by Cary. No advertisements have been found in the contemporary press announcing the availability of Wollaston’s platinum, and as far as one can judge it was not until 1817 or later that Cary produced a printed catalogue listing items offered for sale at his shop in the Strand ; the first printed statement, that “the metal may now be had, at Cary’s, No. 182, Strand, London”, appears in a chemical textbook published in 1810 (26).