Base value of course will be based on the Sterling Weight, the rest would be Age, Rarity, Maker and condiion. Which none of these apply too much, Uniqueness of the back side will add a bit. Without a set your value will hover somewhere around Silver Prices.
Which brings to mind something I have discovered about most sterling pieces in these day. People only tend to pay Sterling value for items. Even when rare or unique, they want the Gram weight and rarely will it ever go over $1.00 a gram. Sad thing is I can post a Mid Century Silverplate spoon and get $10.00, but post a 8 Gram Sterling spoon and you get $6.00, when the prices of silver drop then it seems they start to consider Rare, Unnique and age in the value.
If you want to vase value look at how much sterling is on there, kind of hard to tell how thick, or if Handle is hollow. I would guess to have 40 grams of silver, and if so you will get $35.00 for it on ebay.
