sara, as an eBayer of long standing, it is strictly against the rules to buy "off eBay", particularly if the item is still listed. I have done it a couple of times a few days after an item has finished, if someone has messaged me and asked if the item is still available, can they come and collect it and pay on the spot - that's probably against the rules too, but IMO it's better than the alternative, which is taking the thing to the charity shop.
I'd advise you to do a Buy It Now for £130, then it has to go through EBay and you can pay by PayPal - but check first that he is offering PayPal as a payment option!
He's only got 130 feedbacks so presumably he's fairly new, 130 isn't many - if you click on his feedback number, you can see when he started trading on eBay and look too at other people's feedback - always worth doing if you are not sure.
That's what I'd do!
How much