I think you expect to have too much, yes 70USD is the price to pay when someone less lazy soldered it for you ^^ (and created an app to configure the bridge, organized a production line and ensured customer support).
You can use a Wemos D1 Mini, you’ll only have to solder 3 cable to receive 433Mhz signal, and another 3 if you also wish to emit 433Mhz signal.
Here is an example of 433Mhz receiver/emitter. Here is another receiver, if find this one to be the best I could find.
To avoid at all cost is this kind of module (it’s hard to have a signal 1 meter from the receiver!):
Here you can order the Wemos d1 mini.
If you are really allergic to solder, you might use a CC1101 serial receiver. They are only 10€ but as far as I know, you’ll have to write some code to make it work.
See here for (a little) more info.