Startup Idea: Cross-Platform Marketplace Management Software for Domain Trading

Startup idea to develop a software that facilitates the management of buying and selling domain names and other items across multiple platforms. The program should allow inventory management, tracking of profits over time, documentation of item-specific details, and calculation of cost/fees for each marketplace with the ultimate goal of consolidating sales and profits, thus saving valuable time.

I buy and sell domain names, and other products. I need a program which I can put in and take out items as they come and go. I need a way to organize what my profits are at any given length of time. I need there to be ways to enter descriptions / custom fields for speficic items. Where I have things for sale. A way to calculate cost / fees associated with each marketplace.

I need a way to consolidate cross platform sales etc.

This would save me hundreds of hours a year.