I mean something like this, with bracing to stop the vertical part flexing backward and forward. The standard design, like this, isn't very rigid.

I can't remember exactly how much plastic that used, I think probably about 6-7m of 3mm filament (a 1kg spool is about 130m IIRC)
I don't generally pay much attention to how much plastic things are using, its cheap enough that its not usually enough to worry about.

Gotcha.

This would probably be the one I buy, which looks to have the rear bracing you're talking about - http://www.aliexpress.com/item/Hot-Full-Acrylic-Quality-High-Precision-Reprap-Prusa-i3-LCD-Acquired-DIY-3d-Printer-Kit-with/2026704108.html

Yeah, that looks OK.
The other important things are that it has a heated bed, and can print from SD.
I'd personally be a bit scared of breaking an acrylic frame, and some people do end up having problems with some of those Chinese hotends, but of course those are what make it so inexpensive.
 

http://3dprint.com/88238/electron-3d-prusa-i3/

Very interesting.

It's saying first batch sale over, 2nd batch starting within 48 hours, and the price is $249.

But it also mentions the auto levelling as an extra, need to check that.

I haven't even looked at it tbh, someone posted it on Facebook earlier. You. Definitely want autolevelling.

Looks like the exact same model as a couple on aliexpress for pretty much the same price (but without the panic of missing out on a time limited deal)

http://www.aliexpress.com/item/7-Material-size-225-225-210mm-High-Quality-Precision-Reprap-Prusa-i3-DIY-3d-Printer-kit/32400852250.html

I think I'll wait until I've got a bit more disposable cash, or I impulse buy it, or I've had a few drinks.

Next question - PLA or ABS?

Depends - what are you printing?

Boxes, enclosures, I doubt anything too intricate. No tie interceptors.

ABS then. More durable and stronger. 

(but if the enclosures are big, you'll need a heated bed and maybe some hairspray to prevent/reduce warping)

Hairspray? What does that do? And what's the difference between the two types? Suited to different types of objects? Shall I add one more question mark to my post?

It prevents or reduces warping. Of hair, presumably

Helps the Base Layer stick to the bed (and stay in place/not curl up at the edges).

Abs is stronger* but, generally, it's harder to print such fine details reliably.


*depending how you define strength

I see. Can I use hairspray to make print a 3D model directly on someone's head?

Could I use hair gel or chocolate mousse instead?

If you heat their head to about 160C and they sit very still, sure why not.

I find chocolate mousse a little sloppy for good hold, but you could try a chocolate mouse