Personally, I was thinking to configure network with ER-X for myself, but I quickly started to reconsider to take ER-4/ER-6 or Omnia, which seems to be few magnitudes better. Omnia is great SOHO router, it has better transfer over the air (5GHz on Turris it's between 900-950 [0]) than ER-X in eth-eth (700-800 [1]). If you aren't scarred of having a all-in-one device[6], then it might a great choice if you would like more possibilities, e.g. to setup few more services directly on Turris (i.e. PiHole, Syncthing) with mSATA disk, instead of using RaspberryPi with SD card (:scream:) for this purpose. In terms of pricing (for EU customers) pricing does not sound that bad (if you also looking to have a WLAN network), because ubnt ER-4/RaspberryPi 3B+/UAP Lite (note, it's slower MIMO 2x2) [2][3][4] is about 260+ pounds, for Omnia 270+ pounds.
[0]: https://bluegadgettooth.com/best-openwrt-router/
[1]: https://www.mbreviews.com/ubiquiti-edgerouter-x-review/
[2]: https://skinflint.co.uk/ubiquiti-edgerouter-4-er-4-a1749252.... (~160)
[3]: https://skinflint.co.uk/raspberry-pi-3-model-b-a1785657.html (~30)
[4]: https://skinflint.co.uk/ubiquiti-unifi-ap-ac-lite-uap-ac-lit... (~70)
[5]: https://skinflint.co.uk/turris-omnia-2gb-a1520592.html (~270)
[6]: I have heard following rule of thumb, that networks should be organized to have dedicated devices per given resposibility instead of having such router-switch-nas-godzillas, because of easier replacement in case of failure, maintenance, etc. etc. (just like in microservices architecture).