What does it cost to build and run a custom internal/client portal system like this compared to a practice management platform like TaxDome?

The member reported using Assembly (formerly Copilot) as the container/messaging platform at a cost of $900 per year per seat, with three seats currently in use. The various pages and dashboards built through the vibe-coding tool are then embedded into Assembly per client, so each client sees their own portal within that messaging container. The member still pays separately for Assembly on top of whatever the vibe-coding platform costs.