Interesting thread! Have really enjoyed reading the stories about how armies got so large.
Going back to the OPs question, I have several 8k+ point armies. Once I have a small force, it's more than an exercise in army building. Here's how mine came together:
- Painting: my collection expands simply because I like to paint. My first pass never really leaves me satisfied and have no problem trying again.
- New Releases: some models are hard not to buy. I may never use them in a game but nonetheless feel I need them. Over the course of years, this makes an army huge.
- Deals: I know the cost of most GW
kits. Some of my armies started because I was able to get the models for 25%+ off. My Guard cost less than 50% the retail price and continues to expand.
- Other People's Armies: some of my armies started off as someone else's. Most of my Daemons, Grey Knights and Guard came this way, people just get tired and want to trade or do something else with their life. Maybe the army starts off non-competitive, but eventually it gets there.
- Commissions: from time to time, I do commissions and end up keeping some of the models. Nothing shady, I may be asked for freehand work that's too expensive and be offered a Leman Russ instead of cash.
In terms of the 'big' armies I have:
- Black Legion - 12k points, about 10 years of building
- Daemons - 12k points, about 8 years of building
- Guard - 9k points, about 6 years of building
- Grey Knights - 9k points, about 3 years of building
- World Eaters - 6k points, about 10 years of building
- Dark Angels - 6k points, about 3 years of building
I rarely photograph a large army on a single table, it's hard to do that. You can see pics of some of my Black Legion here.
Now, I just got 2 of the Apocalypse sets, so all the CSM
and Havocs are being updated, the Shadowspear models are being added, I have 2 more Forgefiends done and 3 Lord Dischordants still being painted. I repainted about 30 of the old CSM
sculpts as Red Corsairs and traded some of the 2nd edition models at NOVA
So this army will look very different next time I pull it all out.