I always found LH's fares to be identical ex-BRS, ex-BHX, ex-LHR (with the exception of the small fiasco at the beginning where they hadn't properly loaded fares, and it was returning crazy prices). In almost every case, the cost was driven by the "other leg" (aka FRA-XXX), not the ex-BRS bit.
What was, and still is, painful is LH's YQ. At one point it was £32 per sector, and it's still in the high £20s now. And nearly all flights ex-BRS are 4 sector flights.
As an example, a BRS-FRA-INN flight on LH consisted of about £100 fare, and £176 in taxes, of which £128 was fuel surcharge. The fare + airport taxes made it a viable option over the EZY flight, but the fuel surcharge killed it. A similar problem with long-haul, although not quite as acute.
YQ is a horridly blunt tool, and many people complain that LH's is out of line with the market. It may be that they can command that where they are established, but it certainly hurt when trying to compete against KL/AF.
As for CO - the fares ex-BRS are identical to those ex-LHR. They may have more competition ex-LHR, so the lower fare buckets don't sell out as fast, but it's still a better deal flying from BRS. (I've got great fares for June).