What is the value of a 1821 coin that says dei gratia ferdin vii spanish?

* King: Ferdinand VII

* Composition: Silver

* Weight: 26.5 grams

* Diameter: 38 mm

* Obverse: Legends +DEI GRATIA+, bust left legend FERDINANDUS VII DEI GRTIA.

* Reverse: Legends on top HISPANIARVM REX - shield flanked by pillars between waves and the value VII (7) in the exergue.

Price on Numista: 14-1200 euro

Price on ebay: around 1000 USD (for the 8 Reales coin)