Coentrao is rubbish, nothing less and cost them 30mil and would have gotten a huge wage to go along with that. He's poor defensively, ridiculously aggressive(like Marcelo he likes doing nasty tackles), his crossing/attacking is meh. He's never a 30mil defender in a million years and frankly i don't think he's better than BAE, probably worse.
He's pretty similar to BAE + the red card risk of Ramos(as in competant refs would send him off almost every match he played), thats the best way to think of him. He's worth sub 10mil and sub 60k a week but they'll want a huge price(even if that is a huge part of the transfer fee knocked off) and he'll want well over 100k a week most likely). Would be a truly awful move for Spurs to swap Bale for a ludicrously priced, pretty rubbish left back who would want wages that dwarf everyone elses at the club.