Good RTS game, slightly old. Cheapest I could find and no stupid online DRM to worry about.
Lord Of The Rings: Battle For Middle Earth 2
Command all the races of Middle-earth with 3 all new factions including Elves, Dwarves, and Goblins.
Win the war in the North single-player campaign with all-new story that takes you to places and battles of Middle-earth previously unseen.
Build your own landmark castle with fully customizable and upgradeable fortresses and walls
Create your own hero with all new customized RTS units that are your avatars in-game
Control battles with all-new enemy AI, melee combat, and flanking, adding unprecedented tactical fidelity
Master next-gen unit control with smart formations, battle lines, and planning mode
"Build anywhere" brings creativity and strategy to base building and battlefield dominance
Control the entire war with a high level "Risk" style meta-game on the Living World Map with all new strategic AI
Extend your battlefield with larger than life navy battles at sea