platinum is pricey pricey so if it really is then a good jewelry shop will know. my b/f trades that stuff and idk isn't it like 2,000 an ounc right now?
There must have been a mix-up in communication somewhere - it seems your ring is platinum. Platinum rings are usually marked Plat or "PT" followed by one of the following numbers: 999, 950, 900 or 850 indicating the % of platinum.
The other numbers you found are probably either a style number or serial number.
Platinum is stronger than gold & more expensive per ounce. It's a particularly good setting for a ring as our hands see a lot of action & you want a strong, durable metal.
Your jeweler will know the best way to polish your ring & help you keep it looking pretty forever