In 2005, LEGO released 3 Factory sets, all of these sets have been retired. For that year, the total price of all retail sets cost $230, today those sets are valued around $648, a growth of 182%.
Most valuable 2005 LEGO Factory set
5526 Skyline $459.68
3 sets

5524 Airport

Theme Factory
Year 2005
Pieces 607
Availability Retired
5524 LEGO Factory Airport
Retail $29.99
Value $86.70
Growth  +189.1%
Annual growth 3.4%

5525 Amusement Park

Theme Factory
Year 2005
Pieces 1,344
Availability Retired
5525 LEGO Factory Amusement Park
Retail $69.99
Value $101.20
Growth  +44.6%
Annual growth 2.7%

5526 Skyline

Theme Factory
Year 2005
Pieces 2,747
Availability Retired
5526 LEGO Factory Skyline
Retail $129.99
Value $459.68
Growth  +253.6%
Annual growth 4.7%