Which Technic model to buy next?

mikerobot

I hope this is the right place to ask but what Technic set would be good next? I've bought my brother #42029 (pick up) and #42038 (arctic truck) in the past and he loved them. He built a new shelf in his office for them although he isn't as 'in to' lego as most on this site! :)

Budget is £40 max. What would you recommend. I guess vehicles would be good. Value for money. As complex as possible (he's 40).

I know this is over budget but thoughts on the Drag Racer?

Thanks in advance