2
The solution you have now, may well be the best to date.
I've never tried the following module, but perhaps you wish to give it a try and see if it would suit your needs:
http://dev.xoops.org/modules/xfmod/project/?account
If your looking for transaction based modules, then you also have the zencart port and Hervs new bookshop module which I suppose could be adapted.
Now these modules are still not close to what you are asking for and would require additional work on them.
Quote:
You don't think that they are too many modules for a single operation?
3 is not too many, consider them simply subsections of an account, and if it's not broken then don't fix it.
Kind Regards.
Tom
http://bassmanthemes.com
http://www.xoopslance.com