I few thoughts from my side: typically a badge system in my understanding does ideally not tie a certain amount of money to a badge but would rather tie a certain tier (salary level) to a specific set/combination/number of badges. A certain skillset represents a certain value for the company.
However, I still wonder if the pattern of traditional MbO sneaks in at a certain point in badge systems: people feel "incentivized" to acquire certain badges for the sake of earning more.
We decided for the moment to go for a pure tier system (without badges) that is trying to evaluate market value based on self- and peer-rating backed up by a half-yearly qualitative feedback process of a tier assessment committee. Each member can pitch for a higher ( or lower tier) if they feel treated unfair our sense a misfit. It has served us well until now, working on v2 at the moment to specify criteria of certain tiers a bit better. They are a bit vague at the moment.
So far my thoughts...