In my opinion, for what he's wanting and what is showing, it seems like alot of work for little profit. He even hurts his chances by saying it is the leftovers from estate sales, so the first thing that comes to mind is that everything has been scoured through. Someone who has the storage space and time to wait for it to sell and get top dollar for it could possibly make some money if they sold from a store. But I have a time is money mentality myself, if I double my money on a $200 dollar unit but put 40 hours work into it, that is a loss in my book. I could be totally wrong I have only been  buying and selling a little under 2 years. Someone with more experience want to chime in?

I think while using Global shipping is easier for the seller, the increased costs for the buyer result in lost sales.

I agree completely, I know I have lost sales due to the Shipping and import charges they charge. However I have sold a few items for more money to international buyers, when there was really no domestic interest. For most international countries I feel safer using GSP. I prob would ship to Canada, and most western European countries directly.

And you can only use first class letter if it is under a certain thickness and size as well as a couple of other restrictions, so unless your smalls are light and flat, you have to do first class package, not letter anyway. Here is a link to usps: https://www.usps.com/ship/first-class.htm click on Rules and Regulations tab in middle of page. 

I think they are tryiny to discourage Buy-it-Now/Fixed price lisitings unless you have a store. This is what they sent me in an email a few weeks back:

Our research shows that in many popular categories—particularly fashion and collectible items—listing your items auction-style is the best way to make a sale. That’s why the standard selling fees will be updated to give sellers without an eBay Stores subscription up to 100 free auction-style listings per month* in the following categories:
•Antiques
•Art
•Baby
•Clothing, Shoes & Accessories
•Coins & Paper Money
•Collectibles
•Dolls & Bears
•Entertainment Memorabilia
•Health & Beauty
•Jewelry & Watches
•Pottery & Glass
•Sports Memorabilia, Cards & Fan Shop
•Stamps
•Toys & Hobbies
Starting May 15, 2014, the following changes will be made to eBay’s standard fees:
•There will no longer be an allotment of free fixed price listings in these categories for sellers who don’t have an eBay Stores subscription. The insertion fee to list fixed price in these categories will be 30¢.
•You still have your 50 free listings* every month that you can use for auction-style or fixed price in other eligible categories—or you can use them for auction-style listings in the categories listed above.
•Plus, starting May 15 you’ll have an additional 50 free auction-style listings* that can be used only in the categories listed above.

You find a collector and sell to him for cash only. Then every so often deposit 9,900 dollars in your account until it's all been deposited. You can speed up the process by depositing into several different accounts.

All fine and dandy until you get audited. those deposits probably won't raise flags, but if they decide to audit you for whatever reason and go back 7 years they will probably want the back taxes plus fines and interest on all those unclaimed deposits. I am not a tax professional and I would rather keep my money, but the government has too much power now to ruin peoples lives.

As soon as possible, time and size of storage unit permitting.

If it's something I wouldn't buy at a garage sale then it goes in the donation pile.

99.9% of the stuff I find in these units I wouldn't buy at a yard sale, I'd be donating everything if I adopted that philosophy. ;-) I recently decided to try a new gimmick and had a $1 yard sale recently, everything priced at a dollar or less. It was all stuff I was ready to donate but some good stuff in there. All in all I made over $800 in about 5 hours. The great thing was it was all profit because it was leftovers from various units I had already made my money back on. Typically though if it is not broken or trash, it goes through 1 yard sale, then it gets donated.