Cheapest priced copy (Mirrodin Besieged): $0.35 at Card Kingdom, near mint, their price list as of .
Glissa's Courier 
Creature — Phyrexian Horror · 2/3 · Common · Mirrodin Besieged · #80
Mountainwalk (This creature can't be blocked as long as defending player controls a Mountain.)
Legal inCommanderModernLegacyVintagePauper
Not legal inBrawlStandardPioneer
2 printings · $0.35 to $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Mirrodin Besieged | 80 | Common | $0.35 | $0.49 |
| The List | MBS-80 | Common | $0.35 | — |