Sorry, the Thomas range price structure does not bear this out. A Gordon for instance (the old A3 basically) is over 55 pounds compared to 76 for the new version A1 (Hattons pricing & "Bargains = old stock ignored). A long way over your "30 quid loco".
Also GWR 0-6-0's are 31 pounds vs 25 pound "Ducks" - an even smaller margin. OK, you could argue that the "Thomas" range is a premium range & not a bargain range, but how much cheaper does your "basic detail" model have to be to make it worthwhile producing. Probably have to be sold at no more than 50 to 60% of the "Super" equivalent. I think John Turner gave a good example with his Roco model.
Remember this is a return to where Hornby were 5 years ago, I'm sure that they are NOT going back there.
If you want a cheaper model, your by far better off buying last years model at a discount.
Kevin Martin