Thanks everyone! This is super helpful. Based on your responses, I'm now leaning more towards a trainer.
...and I'd love to bring in to Conte's, but no longer living in DC :(
Safe and happy winter training to all!
If you haven't checked them out, I can't recommend the sufferfest videos strongly enough--structured interval workouts with race footage, including a recently released 2x20 set which is pretty fun (75 min). Totally different from spinervals, which drive me nuts. I now look forward to the trainer workouts. They're also half the price. The hour flies by. Other good tri-based titles are The Hunted (5min, 20 min, and sprints), Angels (10 min OU and 3x8 w/attacks) and Local Hero (series of TT efforts with attacks).
The Sufferfest videos are good. Cheap too, compared to other bike videos.
Worth noting that rollers are the cheaper option. You can grab quality alloy ones from Performance for ~$160 (less during a sale), while the first real quality trainers are in the $300 range (CycleOps Fluid2 and Kurt Kinetic Road Machine).
I have both, and probably use the trainer more now. But I use the rollers to keep it fresh, which is important over a long boring winter inside. Never hurts to keep up on the bike handling skills.
Don't rule out craigslist as well. I found a brand new trainer for $175 from a shop employee who decided against that model, and I know others have found them for the same price range and even cheaper.
According to Tuan, he says that WWE videos are worth their while for indoor training. I'll have to take him up on that.