When starting a small business, how does one properly record "seed inventory"?

Let’s assume someone wanted to start a small, simple business. They go through all of the paperwork to get an LLC, they set up a business checking account and they are ready to go.

Such an individual would need to properly record and report any seed income they may deposit from their personal finances. There are plenty of articles on handling this situation. How to do this properly is well covered on many articles online.

However, what if under the same circumstance one wanted to become an online retailer and instead of investing seed funding, they invested a seed inventory? Tax-wise, how is this handled properly within the accounting books and how to do you report this inventory at tax time?

WHY AM I ASKING?

I’m a video game collector. I love to buy, trade and sell. I’m getting to the point where I could actually turn a decent cash profit in this market and I feel I should move this from a hobby to a legitimate business. My problem is that I don’t know how to handle my "inventory". There are games I own that I love and will likely never sell. I’d rather not migrate these to a business expense of any form, because I see them as personal items. However, I also have piles of stuff I’ve bought in lots that I don’t care to keep and I’d just as soon sell it and make some additional funds.

I’m not sure how to correctly record my "seed inventory" that’s coming from this personal stash of my stuff.

To be clear, though I love what I am doing I really want my income and buying and selling to be handled properly. If I am going to be making significant profits, I need to tax it properly and I feel it’s time to separate this stuff from my personal finances. Still, if I’m going to buy with the intent of reselling in the future, I need to record these items as inventory expenses because, in fact, they are.

NOTE

I have googled this and I can’t find any advice or hot terms that work well for pointing me to any advice. Most articles talk about personally investing in a new business. However, I can’t find anything on starting a business with existing seed inventory, especially so that you don’t over pay Uncle Sam as if it’s magic income that’s appeared out of thin air.

For now, ignore any special state-related rules. I’d like to know what would be the GAAP principles to apply to this scenario and how this generally affects taxes within the US.