In 1971, LEGO released 2 Classic sets in the subtheme Supplemental, all of these sets have been retired. For that year, the total price of all retail sets cost $1, today those sets are valued around $171.
Most valuable 1971 LEGO Classic set
442B 6 International Flags $107.41
Largest 1971 LEGO Classic set
442A International Flags 6 pieces
2 sets

442A International Flags

Theme / Subtheme Classic / Supplemental
Year 1971
Pieces 6
Availability Retired
442A LEGO International Flags
Retail $0.50
Value $63.72
Growth  +12644.0%
Annual growth 7.9%

442B 6 International Flags

Theme / Subtheme Classic / Supplemental
Year 1971
Pieces 6
Availability Retired
442B LEGO 6 International Flags
Retail $0.50
Value $107.41
Growth  +21382.0%
Annual growth 8.9%