Both items are from the Kosta Boda Pandora range designed by Monica Backstrom in 1991. The Blue Dish is 380mms in diameter and has the number 79140. The Jug Green is 360mms tall and has the number 89140. The 1992 250th Anniversary Collection Book shows there were 6 other items in the range.
Kosta Boda 5digit numbers work as follows.
Digit #1 = "type" so 7 = a dish, but 8 = a jug.
Digits #2 and #3 = Year the design was made. Hence 91 means 1991.
Digits #4 and #5 are presumably the number of the pattern or design created in that year. So 40 in this case probably refers to the 40th design that year (I don't know for sure but that seems the likely explanation)
Ross.
See, you never know who has a book or other info that can help you. Valuation, as was said, is what someone is willing to pay at the time you wish to sell.