I laughed when I read the other thread - the 361 is not the solution for every problem! Especially where there is a budget involved.
If I was limited to $400 and needed a saw to cut firewood with, I'd try to find a good used Stihl 038, 044, 046 or something like that. Sure, it would be heavier than necessary for a lot of the smaller stuff, but at least I wouldn't be tapped out on the bigger stuff. I would try my darnedest to buy a good used saw, since they tend to give a much bigger bang for your buck.
But if I was stuck buying new and wanted to take advantage of my local Stihl dealer network, I would take a look at Stihl's 290 and 310. These would make better firewood saws, in my opinion, than any Husqvarna 350 or Stihl 260, neither of which I find to have that much speed or grunt despite their popularity as firewood saws. Having put a fair bit of time on the 290, I think it is underrated for non-professional firewood duty, and what it lacks in power-to-weight will be made up for in reliability.
I know a lot of guys get by just fine with a 50cc/3hp saw for firewood, but I think it may have a lot to do with how you're getting your firewood. If you're dropping a small/medium sized tree or cutting up deadfall, working the entire tree with one saw, then it might make sense to use a 11lb 50cc saw. But if you're going to be taking on bigger trees, or blocking up straight logs of 12"+ diameter, the 50cc saw will get a bit tedious if you have any quantity of cutting to do. By way of example, I blocked up and split a hair under a full cord of 12-16" ash and maple logs yesterday, taking them from the 48" lenghts they showed up in and cut them to 18". Half of the cutting was done with my Husqvarna 154 (a hot 50cc class saw, 3.8hp) and the other half was done with a Dolmar 7900 (79cc, 6.5hp+). The 154 was quite capable at this sort of cutting, but I definitely wouldn't want to have to ask it to run a longer bar and cut big stuff.
At the end of the day, a nice used saw (or steal on a NOS saw...) is probably a better way to spend $400 for an all-around firewood saw. Otherwise, a slower-revving, torqey saw like the Stihl MS290 or MS310 would be a good choice given the number of Stihl dealers in your area.
If you can find a good one at Home Depot's rental department, you could bring TWO home for about $400:
A smaller saw can do firewood duty, but it won't be quick and will require more attention to keeping the saw in its peak powerband than you'd need to devote with a larger saw. This stack of ash and oak was blocked up with the 238se:
These saws cost less than $400 for the pair - the 238 was NOS and the 154 got a new piston/rings and a cylinder hone. The 154 cuts just about as quick as a Dolmar 5100s, at least in my hands: