We've been foster parents for about two years and have had 2 placements (5 kids total).
1. We started in our late 20's - this is just our way of having kids; we're not planning to adopt (but also open to the possibility).
2. We're officially listed for 3-5, but the oldest kid we've been placed with was 3 years and 3 weeks - the youngest was 7 months (they actually got his age *wrong* when they called us about him, so we thought we were getting a toddler...just some info on how the system really works ;) We're hoping to get out of the toddler game next time!
3. It's amazing! It's also hard. And there are really frustrating parts.
The "amazing" part mostly falls under that hard-to-explain joy of parenting where whenever new parents talk about it they make it sound awful and then tell you it's the best thing they've ever done. Although i think there are some joys that are specific to fostering. The community aspect - fostering, to me, is true application of the "it takes a village" approach where we are sheltering these kids while really pushing for their families to fix whatever was the problem and get the kids back home, and that whole process is really joyous when it works. I also think there's a particular joy to seeing your kids flourish when that wasn't always the case (i mean, seeing kids do well is always fun, but it's a bit different when you were completely unsure if they would recover from XYZ).
And XYZ is really the hard part. I know for most people the kids going home is the heart-breaking part, but for us that part was pretty joyous - it was the culmination of a year's hard work on everyone's part to get them home, they were overjoyed (which makes it hard to be too sad), and we know they're safe and happy - if not parented exactly how we would ;) (i know that's not always the case, so that's a big variable). For me the hardest part has been when they show up, because that first sight and first few weeks are when you really see what they've been through - as well as dealing with the trauma of being in care.
And frustrating. That's where my biggest advice comes in: you have to be flexible, and you have to have compassion (and sometimes you just have to roll your eyes or vent or laugh a little). Obviously for the kids, but also for their parents and for the system as a whole. Because all three of those things are going to cause major or minor frustration on a regular basis.
4. We haven't adopted, but my understanding is that you can continue to get some sort of stipend after adopting if your case qualifies as special needs (which can mean health-related, but also often includes older kids, minorities, or siblings). I believe many states also allow adopted kids to continue on Medicaid, which would be a substantial savings.
As for fostering, from a mustachian point of view, the stipend you get for that is absurd. Everything i've read about fostering includes some variation of "Don't do it for the money! You get a stipend, but it is a measly check that will barely feed a child! You will spend your life savings as well as the stipend each month!" Which, well of course don't do it for the money! But, um, i would at best consider myself something like "mustachian light", and i'm worried about the ethical dilemma of not being able to spend the whole damn thing on the kids. That is only true over time, of course, - the kids need a lot of stuff ASAP when they show up and you don't have the luxury of shopping around for good deals or used items, so it's easy to drop a *lot* of money in the first week. But in the long run, even the infant we weren't expecting (and therefore spent something like $1500 on in one weekend...) costs less than his "meager" stipend covers over time. I would also imagine the money aspect is a great deal more complicated with older kids and teens!