Um.... 925 is the purity of the Silver. 925 stands for 92.5% is pure silver, the remainder is additives.
For Platinum 950, that's the purity of platinum, meaning 95% of it is pure Platinum.
As for 14K Gold, it means that 14/24 of the material is pure gold, the other 8/24 is additives.
18K Gold, for example, is 18/24 parts pure gold, the other 6/24 being additives.
24K Gold would be the purest gold, being 24/24 Gold... but without the additives, it's too soft and malleable a material to be worn without risking buckling and denting.
That's not the price of the item(s)... the price would be the market value of silver multiplied by the weight of the piece (plus my labor and the cost of manufacturing).