You'll probably get easy answers along the lines of "you're a moron" but it depends on what you are trying to achieve and what stocks you are looking at. Given that entry and exits are meant to be decided on technical indicators there's no particular reason why you need live charting, theoretically if you buy for the right reasons and set a sell target prior to doing so then you'll be fine (as much as anyone else). The problem occurs when you don't time entries well; Picking up on retraces vs reversals, supply entering etc etc is very hard without you're finger on the "pulse". The hardest thing will be to pick absolute bottoms or tops or even come close, now if you're prepared to accept that and trade within those limitations then you might do ok, but you are placing limitations on your trades that will result in lower profit margins and thus a greater likelihood of loosing overall.
More than anything else live charting is not overly expensive in the grand scheme of things (depending on how much you are playing with) and gives you an insight into market moves that you just can't get from "click and refresh" type trading.
