The Mac book will even second hand command a decent resale price. But I know nothing of Mac except that I suspect they are overpriced along with everything by Apple.
Whether the PC on offer is a decent swap, tricky one. Depends on what you want the PC for?
I personally do not think this is a good deal as it has a basic graphics card,poor PSU, small monitor.
But I would like to see the make/model of all parts before I could work out the second hand value.
But as I said it depends on what you want the PC main use will be.