I watched a recording of the Mexico v Chile match last night and based on what I saw Sanchez isn't worth anywhere near £45m!! Out of the Chile side Hernandez & Vidal stood out slightly ahead of Isla & Sanchez. I was trying to watch the match with the mindset of not knowing any of the players on view even though is was difficult not to pay special attention to Sanchez because we are in for him, but to be honest I thought he was good, but no way as brilliant as everyone has been making out.
OK, it was only one match, but that's my assessment of him based on what I saw. Also, Isla was playing as the right winger, whilst Sanchez was playing a free role behind the main striker. Yes, I'd buy Sanchez, but from what I saw I would say he was worth £10-£15m - £20m at a stretch, but like I said, this is ONLY based on what I saw in one match. To say that he has the potential to become the world's best player seems to exaggerate his ability to effect a game somewhat. I would say he was similar type of player to Jack Wilshire, but he had less of an effect than Wilshire would have had against what was effectively a Mexico U21 side with SIX debutantes in the side!!
If he came to us he'd be competing with David Silva and Silva is way, way way ahead of him and only 2-3 years older. Based on what I saw of Sanchez, I wouldn't be too disappointed if we didn't get him. Hope this personal assessment helps to settle a few worried minds. :-)