If they did a bronze Dalek, I'd really like it to open up and reveal the mutant underneath (or have a swappable central cavity to allow this.) I think, at this price point and level you have to go big or go home. Just producing a big 1:6 Dalek would not be as successful, at this point. Not for $200+ dollars.
Now, if they did more classic Daleks, I think you have some more leeway, there.
Sure, I wouldn't disagree with that either. I guess for me what I really want is for my CO 12" figures - which will shortly have a great Tenth Doctor to be completed by a 1/6 Dalek and I'm not too bothered by what it does (as long as it has wheels!).
That said, daleks would be a gold mine for BC, especially if they 'go big' as you suggest. For one thing, almost all Classic daleks apart from the earliest ones can reuse pretty much the same mould, with a few minor differences in the slats. Ditto then with the electronics. As far as electronics go they could spend thousands on designing their own or they could copy CO's designs (just as CO's dalek electronics apparently closely resemble those of the Product Enterprise daleks!) albeit scaled down (but actually, aren't the PE movie daleks more or less in 1/6 scale?).
Daleks are a licence to print money, people collect them who don't collect any other Doctor Who stuff. As far as the nuWho bronze daleks go, these also come in numerous flavours - bronze, black, black domed and with various attachments for emperor guards etc.
The third kind of dalek requiring a new mould are the early daleks seen in the first two serials and in the movies. Well, there you go - if they could get a licence for the movies too, then to quote William Hartnell, their arses would be in butter. They could even add a Peter Cushing figure eventually which would melt the internet.
Doctors and daleks are a recipe for success, anything else, not so much. Although it would be interesting to see them try out the old Product Enterprise idea of making monster costumes for 1/6 figures and putting them on 1/6 bodies, exactly like the monsters themselves were made - as rubber suits. But I reckon they should park that for a good few years, along with anything else that might appeal to fans (like Masters and companions). What they should concentrate on (IMHO) is Doctors 1-4 & 9, a new blue suit 10, maybe a new 11, definitely a Capaldi figure, and lots and lots of daleks.