一度に => all at once N3
最中に => while; during; in the middle of ~ N3
〜がさいご(が最後) => if you do... negative result N1
Decisive (resolute decision)
[最中「さいちゅう」] => In the middle of A N3
Time, Situation
たが[最後「さいご」] => Once A occurs, B happens N1
Information, Report
といったところだ => Display an amount/level/degree A (程度) N1
Degree/ Level/Amount