I bought my first T206 card two weeks ago (with the help of users on this board

). Now I am getting hooked. I haven't bought another card because I am trying to maintain a safe budget and it's a marathon not a sprint. With that in mind, I have been daily checking auction sites for deals and am trying to stay committed to only the best buys.
So what I was wondering is what guidelines do you have to buying T206's?
For instance, a nice little template to fill out would be.
Maximum I will spend on an ungraded common:
Maximum I will spend on a lot of ungraded commons (5):
Maximum I will spend on a lot of ungraded commons (10):
Maximum I will spend on a lot of ungraded commons (20):
Maximum I will spend on a low grade common:
Maximum I will spend on a SL:
Maximum I will spend on a common HOF:
etc.
When scouring the board, I see a lot of good tips, but no specific prices that one should commit to when buying which is why this came to mind.
Right now I am trying to find ungraded commons for 10-15 dollars. If an auction goes over that, I just let it roll off my back and don't think about it again. I feel that if I stay patient, those deals will come my way in time.
So what are your tricks?