Advice on negotiating commission increase?

Have been doing sales and account management for an event/webinar/live stream production company. I sell and manage, sometimes produce, programs and individual events. Been doing this for my current company for 1.5 years, focusing solely on producing events for Amazon, one of our bigger clients. Started out with 5% commission on whatever I invoice a client, and I negotiated an extra 3% to account for COL in high COL area about a year ago. We got raises and bonuses at the end of 2017, both were meh, no talk about increase in commission. I like what I do and the folks I work with. It's a small company, I have a lot or autonomy, but my total comp is below average for where I live; company offers no health care & prob won't anytime soon, bonus is entirely discretionary, and my base salary is fine but nothing to write home about. Several teams in Amazon have approached me about working full time for them as a program/event manager. Haven't shared this with my manager, but they're probably aware that this might happen. Don't have any non compete clauses. Have started with phone interviews at Amazon and another FANG company. I work a shitload and deliver good results. Have been considering asking for an increase in commission if I get an offer. What's a reasonable amount to aim for? TC at a FANG company would prob be ~40-50k/year over what I make now over 4-5 years, taking in to account sign on bonus and stocks (not to mention not having to pay hundreds a month right now for total dog shit health insurance). I saw another thread that tech sales commish ranges from 10-20%. Not sure how that's calculated and if that also means low base salary. My company sells events and production support/program management. We don't create technology that we sell, so we're not really a "tech" company and I'm not doing "tech sales." The small company I work for now would probably lose its' relationship with Amazon if I leave. We have other clients so it wouldn't be a showstopper for the biz, but it would def hurt. My long term goals are early retirement, and not killing myself by overworking to get there. Any and all advice/pointers is appreciated. This is my first position in account management and sales, before this I was doing production/technical directing.