Can't comment on either course but the cheapest zero to frozen ATPL seems to be about £30k.- but that is distance learning and no accommodation included.
'Course' is not really generic, so you'd better find out what is extra- £23k. sounds very and suspiciously cheap.
The other comment about aircraft not being available is, also, a warning and is one of the commonest complaints about courses with poor maintenance back-up and other people having priority over student training.