The difference between the two is almost negligible.
As indicated by the price difference.
Basically there are only two differences:
1) Sprinter has a rounded head light like CD100 meanwhile the ECO version has a square one like CD 70 type.
2) Sprinter has a gear indicator alongside the speedometer which tells you in which gear your bike is meanwhile the ECO one doesn't have this feature.
Mechanical specifications for both the bikes are exactly the same. The price difference is only Rs 600.
On left hand you have the meter of Sprinter (standard) and the right one is the ECO one.
<table rules="all" id="ctl00_ContentPlaceHolder1_grdPrice" border="1" cellspacing="0"><tbody></tbody></table>
<table rules="all" id="ctl00_ContentPlaceHolder1_grdPrice" border="1" cellspacing="0"><tbody><tr></tr><tr><td class="NormalText" align="left">SPRINTER ECO Euro2</td><td class="NormalText" align="left">110cc</td><td class="NormalText" align="left">Rs. 69,400/-</td></tr></tbody></table>
<table rules="all" id="ctl00_ContentPlaceHolder1_grdPrice" border="1" cellspacing="0"><tbody><tr></tr><tr><td class="NormalText" align="left">SPRINTER Euro2</td><td class="NormalText" align="left">110cc</td><td class="NormalText" align="left">Rs. 71,000/-</td></tr></tbody></table>