The Solitaire 146 piston filler with barrel and cap in 925 sterling silver is listed by Montblanc under article number 1468; the manufacturer's list price was 835 euros (as at 2006). At Montblanc, Solitaire denotes those versions of the Meisterstück with barrel and cap in precious metal rather than precious resin, the 146 being the middle of the large sizes, with a piston filling system.
Measured against that, a well-preserved second-hand example from the 1980s at 290 euros is cheap; at the time such a price counted as a decided bargain, provided the pen came from a reputable source. Condition and provenance are what matter: silver barrels show wear, dents and scratches far more plainly than precious resin, the piston should run smoothly and hold tight, and the hallmark deserves checking as much as the nib. If you are unsure, look at the pen in person before parting with any money.