Being a fairly inexperienced investor, I am seeking some...

Being a fairly inexperienced investor, I am seeking some guidance from EPD holders and others on what to expect on Monday morning with regards to open price as my work often prevents me in following the market at opening and the period soon after, so i am looking at putting in a bid pre market open before i head off to work.
My research to date leads me to believe that the market has over reacted to the downgrade for first half and if yearly guidance comes to fruition then this is an attractive buy. I feel that we should see a bounce on Monday and my intention is to put in a bid at a reasonable premium to the current price to ensure my purchase, but also dont want to get burnt.
Do any observers have thoughts to what might happen?What % increase would be a suitable bid point?

Any guidance is extremely appreciated.