Percentage Profit and Loss - Not so simple

I have a list of items with buy prices ranging from $0.5 to $3000 and quantities can be bought from 0.5 a unit to thousands of units. Here is an

What's wrong with the data?

P&L Percentage This is the profit and loss percentage, the P & L Column is showing a profit however P & L Column is showing a loss.

The Formula used to Calculate P & L=(E3/D3-C3/B3)*D3

The Formula used to Calculate P&L Percentage - A note this is formula used to calculate total percentage NOT row wise=(SUM(Sell_Costs_Proceeds)/Sum(Sell_Base_Qty)-sum(Buy_Costs_Proceeds)/sum(Buy_Base_Qty))/(sum(Buy_Costs_Proceeds)/sum(Buy_Base_Qty))

The percentage should obviously be in postive.

Some key points:

1. Buy and Sell Numbers can be different so profit is accordingly calculated.
2. quantity has a huge disparity some quantities are less in 1 (0.2) and some thousands (17237). Cost is the same some costs are very high and some low.

Here is the link for the sheet