Quick comparison:
Peloton bike EUR 2145 + EUR 39/month - gets you courses and indoor riding
or:
Canyon Endurace AL Disc 6.0 as an example of a very solid entry level road bike - EUR 1299
Kickr Core direct drive turbo trainer (good turbo trainer, there are cheaper ones if you go without direct drive) - EUR 799
Combined EUR 2098 + EUR 15/month for a Zwift membership or something comparable. Gets you excellent indoor training AND now you have a bike you can use when the weather gets better! Spend the rest of the up front money on a big fan for indoor training or clothing for outdoor riding.
I really struggle to justify EUR 1300 as 'entry level'. It might be entry level for being competitive, but if you just want exercise on something decent you can get road bikes for half of that. I have bought (good) cars for less than EUR 1300.
I think that it is more effective to think relative to absolute luxury. The bikes they ride in the Tour de France are $10,000 and so a $1,000 bike is an order of magnitude. Same for cars, and entry level car is like $20,000. An order of magnitude away from Ferraris and Lamborghinis. The $100 bike that most people think are entry level just simply are not worthy of being called exercise/riding material. You will spend more time doing maintenance (fixing the chain and derailleurs) than actually riding the bike. For those that aren’t in the biking world, the components (not the frame) is where most of the money goes. These cheap bikes are only worth it if you never change gears which is ok for the majority of people but then you may as well just get a fixed gear bike.
Very practical solution would be to take the old beater bike and mount it on direct drive or wheel based trainer permanently. Old used bike can be had for close to nothing
Kinda depends on the perspective - if you want to take up road riding as exercise somewhat seriously, it's the price point where the component quality levels off.
Above that price point, component quality goes up in terms of performance, weight, etc, below that price point it requires compromise you notice even when just riding for exercise (lower durability, bad shifts, sluggish ride feel and so on).
In the world of road bikes, I'd propose roughly these categories:
100-400: bad cheapo bikes. Will ride, but no fun and will break and give you headaches soon.
700-1000: Decent bikes, but you have to make some compromises. Fun can be had, will not randomly break because of bad quality components.
1000-1400: Good stuff, not extravagant. Won't have to compromise on much, you can be satisfied with this forever unless you want to be competitive, and even then it'll do fine.
Quick comparison: Peloton bike EUR 2145 + EUR 39/month - gets you courses and indoor riding
or: Canyon Endurace AL Disc 6.0 as an example of a very solid entry level road bike - EUR 1299
Kickr Core direct drive turbo trainer (good turbo trainer, there are cheaper ones if you go without direct drive) - EUR 799
Combined EUR 2098 + EUR 15/month for a Zwift membership or something comparable. Gets you excellent indoor training AND now you have a bike you can use when the weather gets better! Spend the rest of the up front money on a big fan for indoor training or clothing for outdoor riding.