I tried really hard to find out what happens if a team doesn't reach the 85% plateau. Here is what I found out, from Sam Amick - Sports Illustrated:

sam_amick Sam Amick Owners must pay the difference out to the current players RT @OKCChuck hey. If a team doesn't spend the required 85%, what happens to them?
This is absolutely great news to the Nuggets, meaning they don't have to overpay for a mediocre player just to reach the 85% mark. As it stands right now, here is the current situation of the players under contract for this year:

1. Dre - 7,8 mil 2. Al - 6,2 mil 3. Bird - 4,2 mil
4. Gallo - 4,2 mil 5. Moz - 2,5 mil 6. Kouf - 2,2 mil 7. Ty - 1,6 mil
Total: 28,7 mil
The minimum players on a team I believe is 13, thus meaning we must sign minimum 6 others to play for the Nugs. The 2 rookies are a sure bet, who'll make around 2,5 mil combined. 2 other players that I see returning are Triple-A and G-Forbez. I would like to see a front loaded contract offered to Triple-A, something similar to what Nick Collison was offered by OKC last year. I believe a 5 year deal worth between 30-and 35 mil is just about right, but let's pay him 10-12 mil this year and after that, split the difference equally between the remaining 4 years. Gary Forbes could be offered a 2 year 3 mil deal, with a team option for the 3rd year. That means we'll have 11 players under contract, with a total salary of 42.7 mil. I personally think Nene won't resign with Denver, so that means we are 2 players short. One of them could be Chu Chu, at about 700-800 k this season, so we are still one player short. We cand then chose from the players that will get amnestied by their teams, maybe get a decent player with a small contract. However, the most important thing is that the Nuggets should not throw big money at a mediocre player (David West, Glen Davis etc.) just to reach the 85% plateau, they can wait till next year and give the diff between 49 mil and their payroll for this year (43,5 mil in my example) to the current players on the roster.