As I understand it, the OP agreed to buy the 450D for £290 and the lens for £300.
He then paid for this with £360 'cash' and £230 in 'Trade in' of the G9.
The person selling the 450D + Lens has now decided he is not happy with the deal, and is claiming the condition of the G9 as the reason.
Since the deal was based on a particlar value of the G9, then the offer by the OP to 'buy back' the G9 for £230 (the agreed 'trade-in') AND pay the relevant postage seems fair, turning the original deal into a cash transaction.
He then paid for this with £360 'cash' and £230 in 'Trade in' of the G9.
The person selling the 450D + Lens has now decided he is not happy with the deal, and is claiming the condition of the G9 as the reason.
Since the deal was based on a particlar value of the G9, then the offer by the OP to 'buy back' the G9 for £230 (the agreed 'trade-in') AND pay the relevant postage seems fair, turning the original deal into a cash transaction.


