I regularly use the following search to help me identify great deals:
https://www.logos.com/search?limit=60&page=1&ownership=unowned&geographicAvailability=all&sortBy=Savings&filters=language-english_Language%2Bstatus-live_Status
One of the challenges is that most of the books listed in this search are novels. Is there a simple way of excluding novels from the search results?
I use this link for Faithlife ebooks:
https://ebooks.faithlife.com/search?sortBy=Savings&limit=60&page=1&filters=Live_Status%2BBiography%3Agenre-biography_Genre%2BBiblical%20Studies%3Agenre-biblicalstudies_Genre%2BBusiness%3Agenre-business_Genre%2BChristian%20Group%3Agenre-christiangroup_Genre%2BChristian%20Living%3Agenre-christianliving_Genre%2BCounseling%20and%20Psychology%3Agenre-counselingandpsychology_Genre%2BEducation%3Agenre-education_Genre%2BFamily%20%26%20Relationships%3Agenre-familyrelationships_Genre%2BHealth%20%26%20Fitness%3Agenre-healthfitness_Genre%2BHistory%3Agenre-history_Genre%2BMinistry%3Agenre-ministry_Genre%2BPersonal%20Growth%3Agenre-personalgrowth_Genre%2BReligion%3Agenre-religion_Genre%2BPolitics%3Agenre-politics_Genre%2Bgenre-reference_Genre%2BSections%20of%20the%20Bible%3Agenre-sectionsofthebible_Genre%2BTheology%3Agenre-theology_Genre%2Bgenre-philosophy_Genre%2Bgenre-socialscience_Genre%2Bgenre-worldreligions_Genre%2Bgenre-literarycriticism_Genre%2Bgenre-science_Genre%2Bgenre-humor_Genre%2Bgenre-poetry_Genre%2Bgenre-bibles_Genre%2Bgenre-businesseconomics_Genre%2Bgenre-politicalscience_Genre%2Bgenre-psychology_Genre%2Bgenre-bodymindspirit_Genre%2Bgenre-househome_Genre%2Bgenre-selfhelp_Genre%2Bgenre-travel_Genre%2Bgenre-sportsrecreation_Genre%2Bgenre-medical_Genre%2Bgenre-faithlifewomen_Genre%2Bgenre-truecrime_Genre%2Bgenre-law_Genre%2Bgenre-languageartsdisciplines_Genre%2Bgenre-nature_Genre%2Bstatus-prepub_Status%2Bgenre-bestdeals_Genre%2Bgenre-studyaids_Genre%2Blanguage-english_Language&ownership=unowned&geographicAvailability=all
For Logos I tend to browse the sale links on the homepage or my wishlist to spot any great deals. However, this link sorts by discount:
https://www.logos.com/search?limit=60&page=1&ownership=unowned&sortBy=Savings&filters=status-live_Status%2Blanguage-english_Language%2Bavailability-storefront-lo_Available%20At%2Bavailability-storefront-lexhampressdotcom_Available%20At%2Bstorefront-lo_Available%20At%2Blicensingmethod-individual_Licensing%20Method%2Bformat-research_Format&geographicAvailability=all
Only trouble it includes books which aren't really on sale, but over inflated normal prices.
In your search, under Format, adding the facet(s) "Research Edition" and/or "Reader Edition" may help.