[shan]

here you go. This was done using V3.5.x

open product.tpl and look for

{else}
<input type=text size=7 name=price>
{/if}

and change it to

{else}
Email Us For Prices 
{/if}

open products.tpl and look for

{else}
<font class=ProductPrice>{$lng.lbl_enter_your_price}</font>
{/if}

and change it to

{else}
Email Us For Prices 
{/if}

open products_t.tpl and find

{else}
<font class=ProductPrice>{$lng.lbl_enter_your_price}</font>
{/if}

and change to

{else}
Email Us For Prices 
{/if}