Haha, I'm not sure what you mean by "losing your but" ...
My answer would be that from memory, back when I had my longest D2 stint (between S27-S30) I ran a roster of about 550k. Made two consecutive finals but lost in S28 & 29, before winning it at the third attempt in 30.
I've been back down in D2 since then, but I wouldn't be able to tell you what salaries I was running as I didn't need to pay much attention to it. Sadly my country has lost users over the years so staying up in D2 was basically a given, so I just spent a few seasons training and hoarding a little until I decided I wanted back in the top division again, then I bought up a team not with D2 but with D1 in mind.
I'd imagine that 550k figure would put you right up there in title contention for almost every D2 league in the world, you could probably run less if you wanted to tread water and finish mid-table each season.