I dont know much abt Welingkar but yes Sydenham is well renowned in bbay circles (like IMI up north or T A Pai down south). I got to hear negative stuff abt Welingkar/KJS thro some threads on PG and on a TIME bulletin board.
Hence, I will REFRAIN from commenting abt these since I dont know whether those claims are TRUE or NOT.
Sydenham wud be the cheapest as well (32 K p.a PLEASE VERIFY) and assures u a decent placement if u are in the top 3 quartiles which is eminently achievable. I guess it shd be ranked b/w 20-25 among bschools in India if ever there was a comprehensive ranking (MY OPINION)
http://www.cflogic.com/Mgtindia/CetTop.htm might help u decide.