Consistent default values for exchange fees ?

[asmodehn]

Having a look at kraken_btc_usd and kraken_btc_eur the fees are configured for different type of users...

Ideally we should have the default values matching the setup of a new user of an exchange.
We can probably not enforce that they always match what the exchange fees actually are, but we probably can :

• centralize some of the exchange configuration (it's not related with the traded currency pair for example), to avoid inconsistent changes in multiple places.
• keep reference links around in the source, and rely on a developer modifying the default values when the exchange happens to change its fees policy.
• Builtin strategy configuration autocreate ? #41 so that "advanced" user can easily change their personal fee via configuration, once they have traded enough to have their fees decreased by the exchange.

[garethdmm]

I'd love it if someone could do a exchange fee audit on the exchange library, as well as keeping the reference links nearby in the code. Keeping tabs on 20+ pairs as their fee brackets change over time is difficult but would get easier if we had multiple eyes on it, or had multiple people with more focused areas of responsibility.

[itali43]

submitted a pull request (#80 ) that addresses "keep reference links around in the source, and rely on a developer modifying the default values when the exchange happens to change its fees policy."