Low signal in metal building

[tenpinmogul]

I've been searching threads for awhile and found a number talking about using an external antenna in fringe areas and one inside an office building, but none for in a metal building with metal roof. I am a fair distance from any windows or exterior doors and in my office I get hit and miss reception (between 0 and 1 EV bars but often drops to a weak analog signal). Even at 0 bars EV the data connection works well enough, the problem is it too often drops to the analog signal.

I have an external antenna that doesn't help at all (granted, it's actually for 2.4ghz...but I hoped that would be close enough for some improvement), and I am hesitant to buy another antenna based on this one not doing anything. I also can't afford to spend a couple hundred dollars on an amp / repeater, though would be open to that if there was a less expensive one that might work (in the $50-ish range would work but haven't seen any that cheap). Are there any other options? Maybe a directional antenna? I know being in a metal building is a tough situation but the signal does get through, it just needs a little more help. Heck I was even thinking about drilling a hole in the wall to attach a wire to the metal studs! (I know...not likely to help).

Thanks.