Starting of with the cheapest phone with Wi-fi and its a pretty decent phone, the Nokia E51. Almost all E-series phones today areWi-fi Enabled. This is the cheapest second generation E-series Phone. It runs Symbian 60-series OS and comes with good features which make it great phone for businessmen. Things like voice to text, voice dialling and included Voip software.
It looks GR8 in chrome and bronze finishes, very classy.
Currently available the cheapest for Rs. 11,400 on Infibeam.com with free Shipping.