Free Antivirus For Small/Medium Size Of Company

Currently my company is subscribing to Symantec antivirus annually! Due to cost saving therefore the management intend to evaluate the free antivirus software instead. If everything is ok then i will need to implement it. My questions are:-
1) For a company < 80 PC/notebook users is it wise to unsubscribe the current antivirus license and run those freeware softwares that downloaded from Internet? 2) Which will be the best freeware solution (antivirus) in the market right now? 3) For a country like Singapore does it worthwhile to implement those freeware just for the sake to save those few hundred bucks yearly? Please give your valuable feedback and comments on this issue. Thanks in advance.