Advice On Selecting Draped Bust Half Cent?

I would like to add a draped bust Half Cent to my type set. My budget is probably in the 40-55 grade range, and most realistically 45-50.
I would like to solicit the advice of you EAC people and other experts on making a good choice.
I am particularly interested in understanding artificial re-toning. I think I read somewhere that there are artificially retoned early coppers in certified holders, but I don't know if that is true. Is this a situation similar to straight grading "commercially acceptable" cleaned older coins?
Also, how do the market and discriminating collectors view certified retoned coins, assuming my understanding is valid? And how can you identify retoning?
Thanks for your help.