How many inches can a beginning weight lifter add to their chest in the first couple years?

I'm 6'1" 170 lbs, low body fat ~10% maybe?. My chest is 37.5" (!)

I want to start weight lifting, etc, but I'm curious... Should I not buy any clothing for a while? I wear medium shirts and anything larger than about 41" falls into Large shirt territory.

Once I start thinking about it, my winter coats, softshells, fleece, dress shirts, etc. etc. might not eventually fit correctly. I imagine this is frustrating for people losing weight too. Does anyone have any rules of thumb for how many inches a beginner can add to neck, arms, chest, etc.?