This is how I started my collection when higher grades were difficult for me to manage. If an upgrade never happens, at least I still have a copy, and if I do upgrade, I have one I can read without worry (although I've given several to my younger brother who lost his collection to Hurricane Katrina).
Sure, a beater mixed in with a consecutive run of mid grades and better can stick out like a sore thumb, but for me having nothing their is worse because you can't have a run with a gap. My AF15-ASM375 run still has a few Silver & Bronze beaters, including the AF15. I'd have to sell #1-400 in order to upgrade that one and then start over, but that's not gonna happen.