i've bought 3 ltwoo R9 groups on AliX for 180-200 eur. Hydraulic brakes. 2x11. People are happy. You can certainly go cheaper, but i'd say it means you dont need to spend more. There is a law of diminishing returns though, if you spend half as much you'll get something really crap, for eg. A bike needs good shifting otherwise it's very unpleasant to live with.
ltwoo does make a 1x gravel type group, but i know nothing about that neck of the woods. Presumably it's cheaper, as the left shifter is simpler and you skip the FD.
Btw, having ridden the schwalbe marathon plus while commuting in london for years, these used to be bomb proof. If you're only solving for puncture protection, could be worth considering. If you happen to like them, you can then buy a shitty wheelset so they live on that, and you swap accordingly.
Maintaining 1 bike is a lot simpler than maintaining 2.
Thank you! I will have a look.
It's funny you mention the Marathon tires. I've the wheelset that my Merida Reacto came with, that I plan on putting 32 mm Marathons on to start with and use until I feel like spending more on the "new" bike.
There is more reasons why I prefer two seperate bikes. One is that I will always have one "permanent" on the trainer. The other is that if I end up actually want to do gravel then I've the base. Then I can always upgrade wheels and so on.
I'm going for the Velobuild Aero Gravel.