If Shaw went to Spurs, he'd get bumped up to 100k a week, get first team football and can move on again in 1-2 years and start at even bigger wages at a top 4 club. He'd likely actually both play more, have more choice of moves in 2 years(Real/Barca/Bayern might be interested if he does well in europe and is a bit older/more recognised).
Judging by how good Shaw has looked, if he improves at all in the next couple years, 25mil now could turn into more than that in a couple years when he's more proven.
Because Utd just went and handed Evra an extension, will Shaw automatically be first team next season at Utd, would he be at Chelsea considering they have he who I can't spell the name of and big arse on the other side who are a fantastic pair of fullbacks to begin with.
At Spurs he'd be... lol, starting ahead of Rose. If I was Shaw I'd pick games over a particular team at his age, then move when he'd be an absolutely rock solid certain starter at a bigger club if the offer comes along.