Im with Cat on this one.
1000 GBP is not a lot of money in this day and age and my freedom and independence is worth that tenfold, no matter what anyone thinks.
You say he is twice your age, if you were not in such a vulnerable position would you even consider seeing him ? I think you would be crazy to as you might just scupper your chances of meeting someone who is more suitable to your own age.
I agree that cuddling up and wakening up with someone CAN be nice, but at what cost? My freedom ? No way on gods earth would I give it up for this menial amount. 10,000 GBP per month perhaps and I might CONSIDER IT, but not for 1000 GBP. I think you would be crazy to go ahead with this terrible offer.
Keep your independence, you will regret it if you dont. He would be getting you for a couple of pounds per fuck, this is all stacked in his favour, dont fall for it. No one in this day and age needs to be that desperate.
Good Luck.