The upper end of alloy and mid range of steel has a lot of overlap in price tag has a lot of overlap with the cheaper end of carbon fiber, though. Looking at naked frames, the last steel frame I bought the frameset was 1360 Eur, which I thought was pretty fair for a good steel frame from a reputable manufacturer with geometry and looks I like. There's a Trek Emonda ALR frameset on sale for 1200 Eur on the same site. I can absolutely get a CF frame for 1600 Eur, so the leap from a mid range steel or higher end of alloy frames to the more budget friendly end of CF frames is about 400 Euro or so.
Complete bikes relate pretty similarly to each other, a Canyon CF SL7 Disc costs me 2299 Eur, complete with a 11-speed 105 groupset with disc brakes, a set of DT swiss wheels which look decent enough, Canyon finishing kit and a saddle which looks passably useful. A complete Trek Domane ALR with 105 (there are cheaper variants, of course, with Tiagra and finally Sora) costs 1925 Eur at the local shop which hosts Trek (interestingly the same shop has a CF Trek with 105 for less than that, 2020 model in size 56). I could get a Canyon Endurace AL with 105 for also 1799 Eur. All bikes with 105 and disc brakes. So there's not a big leap - looking at Canyon's lineup and examining what is more or less like for like - the premium for (entry level) CF is 500 Eur. Sure, CF prices sometimes do go sky high if you want the high end of it.
If I was buying a CF bike starting from the frame either I'd go with a Chinese made Winspace for 1600 Eur (in the EU) or a EU made Time Scylon for 3350 but I'd get a bike actually made in the EU and with a technology which makes the typical flaws of CF manufacture unlikely to happen.