I start off with $20-60 depending on the payout Then from there depending on the EPC/ROI and other campaigns I might up it somewhere $100-$2000
You are spending $100-$2000 per day? If yes, that's a lot of money unless you have some outside investors.
I'm started adword just $5 + $50 adword coupon..$5 for activation adword account..Now i spend around $40-$50 per month.
It's not hard to ramp up to spending 1 or 2 thousand a day. If you start with a budget of $50 a day and you see that you are consistently make a $25 profit on each $50 spend, then the logical thing to do would be to ramp up. Maybe you kick it up to $100 a day. If the theory holds true, then you should be making a $50 profit off of the $100 a day spend. Repeat the process a few times and you're spending a grand a day in no time.
There is no such answer to this type of question. I can't tell you to set your budget to $x. That would be ridiculous. Estimate the number of times people search on all your keywords. Multiply by your CTR. If you have yet to start, you probably don't know what you are doing so let's use 1%. Multiply by your CPC. That's your budget to maximize your clicks. Of course, you can start lower but you won't maximize your clicks. As you grow, you can increase your budget. It's not a set once kind of thing. Your click rate can increase (you want it to), you may want to increase your CPC. So figure out your budget as shown above. But to tell you without knowing your particulars is irrelevant. Telling you how much I or my clients spend is also irrelevant as you surely are not in the same niche. It would be like saying my car is green. Knowing that fact would be of no use to you.
The minimum depends on your market. If you are trying to brand your site, do the content network, and you can get away with a few bucks a day. If you are trying to sell gaming laptop computers, I would do something like $20-60/day, and set the bids competitively on the search network. I would do phrase/exact match only in this case.
when i started with adwords back in 2005 i was spending up to $150 per day on adwords and made a nice profit. i think the question really is not how big is your daily budget but how good are your ads and how productive are the clicks you are getting from each keyword combination. if you see that the traffic is productive then you shouldnt limit your budget and take all the clicks you can get off the ads to make sales and profit.