The best deals are often for 1-manual and pedal trackers, as they are inherently limited. I've seen prices so low it hurts to not buy it, but I play too much music that requires hands to overlap—for example, trio sonatas are difficult to practice on these. If this wouldn't be a problem for you, these would be a great option. I came close to pulling the trigger on a 2-manual, 2 rank practice organ, but ended up going a different route. I believe it was in the $15-20k range, for what would be $85k delivered new from the same builder. Really great deals can be had if you're ready to go when the right one comes up.

The next question would be how much space do you have available? Many of the organs I see on eBay are designed for chambered church installations, so they'd end up taking up the majority of a normal bedroom for all of the chests. The organs are basically free, but often are too big for houses.

The third, and maybe most important, question is how much of the maintenance and installation will you be comfortable doing? Often, the process of moving an organ will require reconfiguration, releathering, rewiring, etc... You might physically have purchased an organ, but if it's mechanism and switching hasn't been updated in 50+ years, it might prove troublesome to get operational again.

In my own case, I ended up having a custom Hauptwerk console built by an organ builder in Minnesota. When I was done tweaking the specifications, I believe I ended up paying about $8k (I just purchased the console—I had the computer and speakers already) plus the cost of Hauptwerk. I've been very happy with it, though—as with most organs—I might do a couple of things differently if I were going to do it again today... I'd be happy to share more information on this method if you're interested.

Marc

What about some of these Hammonds that are available on eBay for cheap?

That clears up a lot! I don't have room for a pipe organ at my house. I'm mainly considering this as a way to teach myself to play the organ.

I am no organist for sure, but the title of this discussion could be very misleading! Organs on eBay sounds like a nefarious medical site!

There is a six rank Wahl instrument being offered in the current Diapason Want Ads.
I can attest to the beauty and quality of Wahl's instruments. I have a close friend who had one built for him about ten years ago. The organ listed in the Diapason Want Ads would fit easily in an average sized living room or family room.

Unfortunately, I don't have 9' ceilings, so that's a no go.

I saw a couple of instruments I would like to have, but finding where to put them would be an issue.

It depends on your budget, but if you can, I'd get something MIDI capable. If you don't like the sounds, you can run it through a Hauptwerk rig. And definitely a proper pedalboard. Aside from that, for your purposes, pretty much anything will do.

Thanks, all. I've decided at this time not to get one of organs I've found on eBay. They all appear to require a lot of time & money to get into proper working order.