ebay bulk combining duplicates and cleaning / sorting data prior to mail merge

Hi everyone,
I am selling on ebay however I am spending much too much time on the excel sheet which I download 2/3 times a week from ebay bulk site.
Some of the tasks I have managed to automate but some I am unable to do on my own. I can see on this forum that it can be done however my knowledge of vb is too limited to implement.
Please find attached the before and after.

The main task I am struggling with when the buyer buys 2 or more items
I want to combine the rows with duplicate data,
combining data from 'N' in column 'N' xxx+xxx+xxx
add up the values to the total price in 'U'
and then delete the redundant rows.

Problem

(buyer) user id N U
ur_z_rzruzr 3rRzz crc v cu u cx1 £2.50
ur_z_rzruzr 15uuzRT Wcu £2.50
czcucttcc10 1xrutt £2.99
czcucttcc10 rVttRcx cX £6.50

Result

(buyer) user id N U
ur_z_rzruzr 3rRzz crc v cu u cx1+15uuzRT Wcu £5.00
czcucttcc10 1xrutt+rVttRcx cX £9.49


Thank you for your help

attached before / after

jumbledSalesHistory.xls
jumbledSalesHistorysolved.xls

You can add Pivot table:

Delet row between header name and the data (2nd row)
Select all -> Insert -> Pivot data

and choose User Id and Sum of Total price (I also add count of user Id)

Hi thank you !
this adds up the totals for each customer which is my 2nd task
my first task is to combine the items in column 'n' xxx+xxx+xxx
I need this as it gets printed onto the mailmerge sticker so thet the packers know what to pack.