Dabo
made $800,000 his first year at Clemson and they were the bottom of the ACC when he took over. No idea why you are comparing Collins' Year 1 salary to Dabo's Year 5 (or 7 or 9, I don't really know) salary.
Swinney's first head coaching contract in 2009 at Clemson paid him $800,000 a year — the lowest salary in the Atlantic Coast Conference. He went 15-12 his first two full seasons, including his only losing season at 6-7 in 2010.
Swinney is 97-15 since then, making the past four college football playoffs — Clemson's only miss was the inaugural edition after the 2014 season — and won two national titles, both over Alabama.