That's exactly what we just did. We were going to rent points from someone to try out BLT but didn't want to miss out on the lounge. We could have waited until 7 months out but didn't want to risk availability of a theme park view room. So, we did the only logical thing and bought a new interest on the resale market.
In all seriousness, we considered adding on ~100 points through DVC as an alternative and a quicker way to book, but the prices have gone up so much to buy direct that we simply couldn't. So, we put in a low bid on a contract that met our needs, and it was accepted without counter and also passed ROFR. Our "patience" in not pulling the trigger on the direct buy but putting in a knee-jerk offer on a resale was rewarded, and our desired time frame was still very available after we closed.
Based on other BLT interests passing ROFR, I can't imagine we'd do much worse than breaking even if we chose to sell, and THAT provides me significant piece of mind.