I would rather the £30k marketing budget, that way it will be the customers you want, in the areas you want, at the prices you want, and they will be buying you.
Also if your allready in the buisness you will know what works and what dosent for you in your area, so you shouldnt be wasting the budget, like most of us do when we start.
I take it you are one of the first people he has offered it to at that price, and i can see why he thinks its worth it because we all work so hard to build our little empires, but my guess is after a while he will get deflated at nobody being interested at that sort of price and his expectations will come down along with the price.
It wouldnt suprise me if he ended up selling the van and t/m for there true value and just passing the work on to there new owner to be nice. His best bet is just employing a young tech for a couple of hundred a week, and keeping the rest for himself.
ps, no disrespect to the guy
but imo £55k a year is a job not a buisness, it has very little re-sale value