In 1999, LEGO released 5 Duplo Building Sets sets, all of these sets have been retired. For that year, the total price of all retail sets cost $54.
Most valuable 1999 LEGO Duplo Building Sets set
2588-2 Safari Building Set $19.54
Largest 1999 LEGO Duplo Building Sets set
2467 DUPLO Bucket 86 pieces
Most owned 1999 Duplo Building Sets set
3036 Large Bucket
5 sets

2300 Small Bucket Green

Theme / Subtheme Duplo / Building Sets
Year 1999
Pieces 48
Availability Retired
2300 LEGO Duplo Small Bucket Green
Retail $6.99

2466 Medium Yellow Bucket

Theme / Subtheme Duplo / Building Sets
Year 1999
Availability Retired
2466 LEGO Duplo Medium Yellow Bucket
Retail $12.99
Value $14.03
Growth  +8.0%

2467 DUPLO Bucket

Theme / Subtheme Duplo / Building Sets
Year 1999
Pieces / Duplo figures 86 / 1
Availability Retired
2467 LEGO DUPLO Bucket
Retail $12.99

2588-2 Safari Building Set

Theme / Subtheme Duplo / Building Sets
Year 1999
Pieces 78
Availability Retired
2588-2 LEGO Duplo Safari Building Set
Retail $10.99
Value $19.54
Growth  +77.8%
Annual growth 2.2%

3036 Large Bucket

Theme / Subtheme Duplo / Building Sets
Year 1999
Pieces / Duplo figures 70 / 1
Availability Retired
3036 LEGO Duplo Large Bucket
Retail $9.99
Value $16.77
Growth  +67.9%
Annual growth 3.7%