I found F2P perfectly fine, actually. I only resubbed temporarily because I found a cheap 60-day card on ebay, and the price for it plus Makeb as a subscriber was essentially the same as Makeb for F2P. I will be going back to F2P at the end of the week, and I should be fine. I have the unlocks I need to essentially have the same experience. The only hitches are (a) the 350K credit cap, which requires some planning and (b) the RE chance dropping to 10%, which is a pain but manageable.
OP, why do you need to make 500K a day at the GTN? What does that enable you to do? I get by on 350K quite easily as I adventure around. Maybe I am missing something.