Do not underestimate a software RAID.
Software RAID would typically provide the same, if not better reliability than an entry-level server hardware RAID controller.
Certainly, a software RAID implemented over motherboard's ATA ports would be noticeably more reliable than a setup involving
a $20 FakeRAID card from a corner store.
Software RAID is easier to move around from server to server.
It does not require an identical replacement controller in case
of a controller failure, which is sometimes a hindrance with server hardware.
Just remember to always move the disks together.
In RAID 0, RAID 1, and RAID 10, the hardware RAID controller does not provide
any computational power benefit because there is nothing to offload.
Most modern SOHO and small business NAS devices, like Synology, QNAP, or NetGear,
use a software RAID (Linux/mdadm).
The significant side effect is that you cannot reliably boot from a software RAID.