DeMignon: Kwintek is right, there are some more examples for risen base prices.
From $14.99 to $19.99
- Read Only Memories (Indie: MidBoss / MidBoss LLC) [from $14.99 to $9.99 to $19.99]
- Shardlight: Special Edition (Indie: Wadjet Eye Games / Wadjet Eye Games)
- The Solus Project (Grip Games/Teotl Studios / Teotl Studios)
- STAR WARS Empire at War: Gold Pack Lucasfilm / Disney)
- Technobabylon: Deluxe Edition (Indie: Technocrat / Wadjet Eye Games)
From $14.99 to $16.99
- 1849: Gold Edition (Indie: SomaSim / SomaSim)
- Subterrain (Indie: Pixellore / Pixellore) [from $14.99 to $16.99 to $14.99 to $16.99]
From $5.99 to $9.99
- Guilty Gear X2 #Reload (Arc System Works Co. / Blue Moon Red Owl)
- Guilty Gear Isuka (Arc System Works Co. / Blue Moon Red Owl)
- Seven Kingdoms 2 HD (Enlight Software / Enlight Software)
- STAR WARS: Rogue Squadron 3D (Lucasfilm / Disney)
On the other hand, by far the majority of price changes were for a lower price. So it's definitely no general trend for a high rise in prices.
Also, most (if not all) of the $9.99 Interplay games were once $5.99, although that change was late 2012.