Urgent Help

I have a list of 100 values (prices in figures) in a single column. in next column i have their code names. i want that for each value, anyother value which is within 10 dollar range, less and more, their codes should show up in third column. E.G
2000 A D,B
2009 B A,G
2020 C G
1993 D A
4000 E
700 F
2015 G B,C

A very convoluted solution using only built-in worksheet formulae is in the attached alongside an easy to use user-defined function.