Blizzard's Hearthstone: Heroes of Warcraft is about to expand with singleplayer content in the shape of Curse of Naxxramas and the pricing for the content has now been announced.
The adventure contains five wings, with a new wing opening once per week in this order - Arachnid Quarter, Plague Quarter, Military Quarter, Construct Quarter, and Frostwyrm Lair. If you begin playing during the launch event you'll gain free access to the Arachnid Quarter. You can then buy the next four wings at £4.99 or 700 gold each or various bundles depending on what wings you already own (£17.49 for all five wings - £13.99 if you only need four).
You're then left with the option of either paying with real money or using in-game gold, gold you may rather use for packs perhaps. Regardless you can always try out the Arachnid Quarter to see if the experience is worth the extra money.