First off, I am anything but an API god. :D I have one published script that took me forever to hack my way through. I use a lot of scripts, though.
One of the reason I used PurseStrings instead of CashMaster was that the stores were set up on the tokens GM notes, instead of a character. Tokens take up little to no overhead, while character bloat can kill performance. I have found that once I set up stores though, I never actually used them. It's a good idea, but it just doesn't suit my play style. I mostly use PS for assigning and divvying loot. I have a macro that uses PS and ChatSetAttr (and for one command, Universal Chat Menus). I can use it to assign or divvy coins, or write any specific item to a character sheet's treasure field. It can also report the treasure or coins of a selected character.

/w gm &{template:npcaction} {{rname=Purse Strings}} {{description=[Help](!ps --help) | [Config](!ps --config)
[Set Up Token](!ps --setup) | [Set Party](!ps --party --reset)
**Party**
[Split Award](~PS-Distribute)
[Award Same Amount to All](~PS-Distribute)
**Selected Players**
[Give Money](~PS-Add)
[Take Money](~PS-Subtract)
[Give Item](~Give-Treasure)
**Report**
[Cash](!ps --show --whisper)
[Treasure Items](~Report-Treasure) *Single token*
[Equipment List](~Equipment) *Single token*
}}
This chat menu calls up a number of other commands on my Macro Character Sheet. I deeply dislike the rigmarole of escaping queries in roll templates, so I make my macros modular. It also allows me to use the sub macros in other menus. For instance, the equipment reporter I use as part of other macros that make character reports.
Here are the ones it calls:
PS-Distribute
!ps --dist ?{Distribute amount between selected characters, separated by spaces|100gp}
PS-Add
!ps --add ?{Add amount to selected characters, separated by spaces|100gp}
PS-Subtract
!ps --subt ?{Subtract amount from selected characters, separated by spaces|100gp}
Give-Treasure (appends the entered item to the treasure field of a selected token on its own line)
!setattr --sel --replace --treasure|%treasure% \n ?{enter the treasure to give to character of selected token|object}
Potioner (Not listed here as it would require its own entry, i use a complex macro with discounts and other stuff. I have removed it from the code, though it still shows on the screen shot.)
Report-Treasure
/w gm &{template:npcaction} {{rname=@{selected|character_name}}} {{name=Treasure Report}}{{description=@{selected|treasure}}}
Equipment (This one requires the Universal Chat Menu API, by GiGs)
!chatmenu @{selected|character_id} {template:npcaction}{{rname=@{selected|character_name}}}{{name=Weight total @{selected|weighttotal} lbs.
Encumbrance = @{selected|encumberance}}}{{description=CHATMENU}} --separator: | --title:Equipment --repeating_inventory|itemname|itemcontent!