So far the only overwhelming benefit of the SDS/SDR/RTL design is that it handles LSM and other P25 simulcast modulation quite well. There are more downsides to it, however, including the higher power usage vs a traditional design. The 396XT, for example, had decent runtime using just three readily available and cheap AA batteries, and that scanner was capable of trunking. Aside from "this is the way of the future", I can't really see much point in designing what amounts to a neutered SDS series scanner that will no longer trunk-track.
I'm also not sure how you'd get all the way down to the $250-$300 price point simply by removing trunk-tracking. You still have to pay the DVSI royalties for AMBE+2, you'd still need a big Li-Ion battery to power the RTL chip, essentially the same design as the SDS series, oh yeah and no doubt the requirement to pay the $60 DMR upgrade and $50 NXDN upgrade on top of the base price. Now we're all of a sudden back up in the $400 range, for conventional only?
The SDS series, for as good as it is with simulcast on the upper 700+ bands, has well documented issues with reliable reception in the VHF and UHF bands in high RF environments, in spite of any firmware or "filter" tweaks.
Bottom line is that it would be cheaper and more convenient for end-users to essentially add digital modulation to the BC125AT than it would to come up with a completely new design, or to use the SDS platform as the basis for a non-trunked digital scanner.