The main benefit to using this one even with 5-10 gallon batches would be that it's one I can find at a good price without shipping, that I could also most likely get my money back for if I didn't feel it was worth it. I do have 19 gallon kettles too so despite my 10 gallon mash tun I could do 15 gallon session beers. The main thing I'm worried about is with the increased diameter how much beer I would have to leave in the keg when I transfer.
Can I ask where you found all of those oversized corny kegs? I don't have much of an idea where to look for them other than ebay.
I think it'll be a more difficult to sell than you think. If it's still for sale, it's obviously not in major demand. I think the weight is the biggest thing that would stop me. However, I won't lie though. I'd be tempted to jump on it.
I would use it to ferment big batches of cider. But my point is, for smaller batches, it's going to be a beast to wrestle with being 100# dry. I see no benefit in buying it because it's the only option unless you use it for big ass batches. Cleaning it is going to be a pain because it's heavy. I think you'll eventually stop using it after a while unless you get a decent system together.
I see some OBO eBay deals where you can probably get a 10gal shipped for about $150. I also see some for local p/u if you're close to them. But you'll need posts. I lucked out getting a bunch of liquid Firestone posts from adventures in homebrewing when they had them for $5.
Anyway, I bought 4 of my 10 gallon kegs off eBay. I did an OBO deal on 4 brand new in the box portable eye wash stations. It ended up being about $400 shipped on all 4. I had scored a "free" 14.5gal blichmann conical from buying a huge lot of gear and selling almost everything for a nice profit and stil kept a few things "free" like several corny kegs, a 15 gal blichmann boilermaker w/ FB, the conical and an awesome 5 gallon squaty corny. It's like a 10gal cut in half. I've only seen one other like it and it's on eBay now.
I hated the conical, so I sold it for $600 and used $400 to buy those 4 ten gal kegs. I got several more off CL. I paid less than $50 on average for each of mine.
One friend scored three 10 gal off CL. I traded him one for a SS dual faucet tower that I bought for $25 plus he gave me $25. So that one was "free"
Two of the ten gals came from another friend who got both off CL and traded me both of them for 5 corny ball lock kegs that I paid nothing for also.
I just got the two 15 gal ones off CL for $75/both.
I actually had 11 ten gal, but I sold two of them. I've been buying/selling gear for about 3 years now. I've come across a lot of amazing deals. I even managed to score 3 of the 1 gallon Taylor kegs for $150 shipped. They sell for well over $100/ea plus shipping if you can even find one.
So if you keep an eye out and are patient, you will find them too.
That photo is an older one, but it shows most of the tens. It also shows the 13 that I sold.