Gathering quality increase should be incremental not gated by a specific number or threshold.
If a player equips a axe that gives a 30 increase to the gathering quality, then that 30 points needs to have an affect. Not wait until the player hits a 300 or 700 quality check before an increase in quality is seen.
Recommend to give the actual percentages as a tool tip over the character sheet section for 'quality', 'speed', ect.