Remote Analyst: How much would you pay an analyst to work MTW, Thursday remote, and Friday off?

I work for a super-lax cultured, boutique capital markets brokerage with 5-guys in my office.

All I do is farm markets for emails, get comps, write-up parts of OMs, and manage our database of capital sources and sponsors. They pay me $15/hr x 45hrs/week = ~$35K (and that's automatic; none of us are in there more than 40hrs/week)

I've been there 6 months now and the other analyst (in our sister office) is going to jail for reckless driving for a month. I'm sick of the work (they know I've made a sincere contribution and doing monotonous work for little pay) so I think I will tell them, if they want an analyst, I want same pay for four-days/week, and remote Thursdays... If they don't like the result, we can reevaluate. Otherwise, they can farm their own emails...

PS: Before you say they'll replace me, this is a company with very little overhead and I persisted my way in, created my own role, and have been acknowledged for how much value and efficiency I've brought. They got a lot of bang for their buck with me. What they really need is to outsource this kind of work and I'm the most reliable person to do that.

So how much can I charge for this? Should I do it 2 days remote?