First and foremost, I AM NOT A WELDER. I only have very little experience. But that experience is very much related to the OP's desire. Wireframes.
I agree, the HF welder is crap. But its very very cheap crap that will work for at least part of what the OP is wanting to do. There are several tutorials on converting it from AC to DC and I plan on doing so this summer which appears to improve its performance considerably for minimal additional cost. However, out of the box it does work and can work for your needs, at least on the wireframe aspect. And it can do so on a very small budget. I used it to make this last year:
It went on to become Serena's disco ball halloween costume.
You are NOT going to weld aluminum with it. You are NOT going to weld structural steel with it. It will weld wire of most gauges we will likely be using for wireframes in our projects. It will weld thin mild steel (1/8" rated but I have done thicker though not pretty). It is NOT the best welder by any stretch of the imagination. It is the cheapest though
Under a hundred clams and you can be making blinky stuff. And it runs on standard 115v. Many of the other welders folks above recommended require 230v. So if you don't have that in your garage/work area, then you are going to either have to stick with smaller cheaper 115v welders or you are gonna need to run a 230v circuit for the welder.
If, and I repeat IF you can afford a better welder, then I would. The HF flux welder spits like a major league pitcher, mainly because its flux but also because its AC. DC conversions do seem to help with that according to everything I can see/read. I will likely find out this summer when I convert mine. At the time, I wasn't expecting to use it much after the disco ball project. I mostly considered it a cost of making the costume and mostly as a consumable and basically a throw away. However I have found it handy to have and used it for tweaking and fixing other odd projects around the house. Had I known I would end up kinda liking welding and have any further use of it, I probably would have opted for one of the Eastwoods. I am not sorry I got the HF cheapie flux welder. IIRC, I think I got it for around $80 on sale with a coupon and considered it a disposable tool. It got the job done, it did more than I asked of it and welded stuff bigger than its rated for. I still have it and will still use it.
Welding wire was, well, how can I say this. Um. A PITA. Never having welded before, took no lessons, and had no tutor or mentor made it a challenge. There is so little room for error before you burn the wire and thats a hard lesson to learn too. Welding flat stock and hardware was a piece of cake compared to thin wire. So prepare yourself for some initial frustrations getting your first wireframes done. Consider them practice pieces. And, if you know a welder, see if you can pick his(her) brain or get a mentor. Wish I had one.