Halo doesn't actually work as an androgen much, its extremely weak at the AR. It's 9-fluoro-11-hydroxy functions were made to closely resemble corticosteroids, because at one time it was believed AAS worked predominantly through blocking the GR. And that's really what this drug does. really, really well. It blocks the GR and the 11beta-HSD's (that convert cortisone to cortisol and back). Similar to other GR blockers, you will get typical effects associated with low cortisol : mood swings, repartitioning away from subQ fat, shortness of breath when doing something physically exhausting, large push in hematocrit as a result, increase blood pressure and because your stress response is hampered, a shorter fuse.
For this reason Halo is typically a great drug near coming off a cycle (for those that cycle) and towards the end of a cut (for people that blast and cruise). This used to be a relatively cheap compound. Because it didn't really build mass, at all, it wasn't in vogue and they would throw it at your head for cheap. Now, its still good, but for what it does, and given the alternatives, I don't think I'd spend on it what it costs (costs 2-3 times what other orals cost typically now).
If as you say you got a good deal, then naturally you go for it. If you can pick the stuff up for the price of dbol or winny, you probably should. However with the ease and low cost with which you can get drugs like masterone and tren these days, I don't think halo is often a good buy.