If you're smart in FA, you know a few key concepts.
1: No team let's a good to great player get away. If they do it's for certain reasons.
A. They're broke.
B. The player and organization have some conflict
C. The player is hitting twilight years or coming off an expensive contract
2. Know positions of depth or value either via the draft or market. Teams who wildly doing so because they believe they need an impact player, but at least half of the time (if not more) they are paying extra due to the limited market created by "1" as good to great players are never let go.
3. Know your position and what you can spend for each section of the team (DBs, D-Line, O-Line) as a total concept. Investment is about not investing too much on one section of a team.
4. Have a spending/cut plan for the next 5 years. Foresight wins and knowing where to strategically place cap flexibility is what allows good teams to maintain quality teams for years. That and an All Pro QB usually helps.
5. Know the market. A slight over/under in either direction is not a big deal. It's big overspends that kill teams. If the RB market is 8 mil/yr, then going up to 10 mil is not a big deal, but beyond that, you're trying to figure out if spending an extra 4 mil for that position is going to help you or not. That 4 million could be difference between landing someone like Hunter or not. Better to save a little or stay on market for RB and have that extra money to spend on another high quality free agent.
6. You do not need to spend everything. If the cards land well, then great. If they don't, then do not make a move just to make a move. I'd rather wait and see what happens when more cuts happen. Sometimes you can find gold there before the start of the year. It's okay to have some money remaining.