Aelia Eudoxia was the most powerful woman in Europe at the end of the IVth and the beginning of the Vth Century. She married the Byzantine Emperor Arcadius in 395. Arcadius had a weak character and was totally dominated by Aelia Eudoxia, who was even involved in several legal matters. On 9 January 400, Eudoxia was given the title of an Augustae. This gave her the right to depict her image in coins until her death on 6 October 404. Here you can find more information about her.
The solidus of Aelia Eudoxia are very rare, but a few hammer prices can be taken as references: this specimen in a lower condition was hammered for 6.000 CHF in 2010; this other one in a higher condition was hammered for 8.500 euros in 2012 (the hammer prices of that particular auction were all very high). More recently, this coin was hammered for 4.500 euros and this one for 6.500 euros. Hence, I would not bid more than 7.000 CHF for the coin in the auction.
Description from the seller
AELIA EUDOXIA, WIFE OF ARCADIUS, 400-404
Mint of Constantinopolis Solidus 402-403. No officina letter.
Obv. AEL EVDO – XIA AVG Draped bust to r. with pearl necklace, pearl diadem, being crowned by manus dei.
Rev. SALVS REI – PVBLICAE Victory seated to r.on cuirass, pointing to shield with Christogram on column in front of her. In exergue CONOB.
RIC 28 var. (shield behind cuirass). LRC 273 var. (shield behind cuirass. Depeyrot 36/1.
4.47 g. Very rare. Tiny edge nick. Good extremely fine.