I managed to add 12% to my position with the recent weakness at just under $51 the other day. It's only a short time that I've owned IP and have had one sale at ~$62 and one buyback so far. The sale was to trim 10% of the position and this buyback replenished inventory with a little extra.
My starting price was $52.88 last August. So, exclusive of dividends, I'm about break-even with a few more shares and about the same initial cash in reserve.