If you’re looking for cheap… what would recommend is instead a Mini-PC like the HP EliteDesk 800 G2 DM or the Dell OptiPlex 3050 Micro.
For a small NAS and self-host a few services even an old laptop will do it, however there are advantages to picking a mini PC. Those machines are quiet, don’t require much power and some can even fit a 2.5" hard drive so you won’t need external hard drive enclosures. More on that later.
For eg. for 100€ you can find an HP Mini with an i5 8th gen + 16GB of ram + 256GB NVME that obviously has a case, a LOT of I/O, PCIe (m2) comes with a power adapter and outperforms a RPi5 in all possible ways. Note that the RPi5 8GB of ram will cost you 80€ + case + power adapter + cable + bullshit adapter + SD card + whatever else money grab - the Pi isn’t just a good option.
Aside from the big brands like HP and Dell there are other alternatives such as the trendy MINISFORUM however their BIOS comes out of the factory with weird bugs and the hardware isn’t as reliable - missing ESD protection on USB in some models and whatnot.