I hope you are paid what you wanted to be paid. On average my experience has been that Amazon's offers are lesser than Google and Facebook's. Not to mention no free food which would be okay if Amazon paid more but that is not the case.
That's the direct implication, however. Unless you claim offers are decoupled from the labor market's value of an individual, which is certainly a novel idea I'd be interested in hearing about.
In that case most tech people are "lesser" than investment bankers. I didn't say anything about an individual's worth being tied to their offer. That is asinine in my opinion. You are projecting that by yourself. If you want to stick to numbers ask your peers who got offers from all 3 how they stack up. I also know the perks at Amazon suck. Food is a big perk for me and not having that is a straight 4k+ hit to your comp. 401k matching plus mega backdoor 401k , better health insurance. Even keeping absolute numbers aside Amazon is a penny pincher when it comes to its employees.
You can be the smartest engineer and have a bad interview day. Your offers then won't reflect your true "labor market worth". In the absence of a solid evaluative metric to judge a person, tying what an employer pays them to their worth is stupid. If you work for Amazon my unsolicited advice would be to get out if you want to be paid more.