That's awesome - I love the idea. Even if it doesn't pan out as a "money maker" for you, it's a neat hobby that will provide all kinds of interesting memories. I suspect you'll have all kinds of stories about prospects thought were "for sure" going to make it big, who ultimately flopped, leaving you with a worthless card and other stories about guys who you successfully bought low on who became stars. I have a display cabinet full of autographed baseballs. I ought to do a better job labelling who's who, but I know I've collected several young prospects along the way with a similar mindset. I don't expect to make any money off it, but the memories will last a lifetime.
I don't know much about card collecting, but are these Bowman autographs the best ones to go after?