In todays market seems a fair price to me. Why hes getting negativity because he was sent out on loan to league 1 as a just turned 19 year old to get some experience I dont know. Just goes to show people dont understand football.
Hes only just turned 22, got 3 full seasons under his belt whilst also progressing in standard and more than coping with it every year, and hes also become a full international in that time too - another level he looks more than comfortable with.
In his careeer so far hes averaged around 1 in 3 from that wide forward / winger position. Thats a more than decent return for someone who still has many years in front of him, hopefully for Wales at the highest level possible.
Personally, I think he will flourish at Spurs.