Shell Programming and Scripting

nokia1100    123,000
nokia2100    66,000
samsung123    11,000
samsung456    23,000
iphone432    234,000
iphone678    123
cherry679    11,000
cherry123    67,456
nokia660    345,222
nokia_series    123,321
nokia4200    23,645
samsung_series    23,978

nokia1100
iphone678
nokia4200
cherry123

nokia1100    123,000
iphone678    123
nokia4200    23,645
cherry123    67,456

$ awk '
    FNR==NR{arr[$1]=$1;next}
    $1 in arr{print arr[$1],$2}
' list.txt file.txt
nokia1100 123,000
iphone678 123
cherry123 67,456
nokia4200 23,645

And a different solution:
$ while read modelnum; do awk -v M="$modelnum" '$1==M {print}' file.txt; done < list.txt
nokia1100    123,000
iphone678    123
nokia4200    23,645
cherry123    67,456

awk 'NR==FNR{a[$1]=$2;next}
a[$1] {print $1,a[$1]}' item.txt list.txt

grep -f list.txt item.txt

cherry123 67,456

[root@powerbroker pravin]# cat f3
nokia1100    123,000
nokia2100    66,000
samsung123    11,000
samsung456    23,000
iphone432    234,000
iphone678    123
cherry679    11,000
cherry123    67,456
nokia660    345,222
nokia_series    123,321
nokia4200    23,645
samsung_series    23,978

[root@powerbroker pravin]# cat f4
nokia1100
iphone678
nokia4200
cherry123
test


[root@powerbroker pravin]# awk 'NR==FNR{a[$1]=$2;next}
a[$1] {print $1,a[$1]}' f3 f4
nokia1100 123,000
iphone678 123
nokia4200 23,645
cherry123 67,456