In 1996, LEGO released 6 Castle sets across 3 subthemes, all of these sets have been retired. Subthemes for that year included Dark Forest, Royal Knights, and Value Packs. For that year, the total price of all retail sets cost $92, today those sets are valued around $2,910, a growth of 3048%.
Most valuable 1996 LEGO Castle set
6079 Dark Forest Fortress $1,679.20
Highest growth 1996 Castle set
1804 Crossbow Boat +3668.84%
Most owned 1996 Castle set
6024 Bandit Ambush
6 sets

1752 Boat with Armor

Theme / Subtheme Castle / Royal Knights
Year 1996
Pieces / Minifigs 21 / 1
Availability Retired
1752 LEGO Royal Knights Boat with Armor
Retail $1.99
Value $72.27
Growth  +3531.7%
Annual growth 9.0%

1804 Crossbow Boat

Theme / Subtheme Castle / Royal Knights
Year 1996
Pieces / Minifigs 21 / 1
Availability Retired
1804 LEGO Royal Knights Crossbow Boat
Retail $1.99
Value $75.00
Growth  +3668.8%
Annual growth 8.3%

1843-2 Space and Castle Value Pack

Theme / Subtheme Castle / Value Packs
Year 1996
Pieces 48
Availability Retired
1843-2 LEGO Space and Castle Value Pack
Retail $7.99
Value $348.59
Growth  +4262.8%
Annual growth 11.7%

6024 Bandit Ambush

Theme / Subtheme Castle / Dark Forest
Year 1996
Pieces / Minifigs 59 / 2
Availability Retired
6024 LEGO Castle Dark Forest Bandit Ambush
Retail $6.50
Value $227.34
Growth  +3397.5%
Annual growth 9.7%

6046 Hemlock Stronghold

Theme / Subtheme Castle / Dark Forest
Year 1996
Pieces / Minifigs 216 / 5
Availability Retired
6046 LEGO Castle Dark Forest Hemlock Stronghold
Retail $23.99
Value $507.95
Growth  +2017.3%
Annual growth 7.9%

6079 Dark Forest Fortress

Theme / Subtheme Castle / Dark Forest
Year 1996
Pieces / Minifigs 464 / 7
Availability Retired
6079 LEGO Castle Dark Forest Fortress
Retail $49.99
Value $1,679.20
Growth  +3259.1%
Annual growth 9.4%