How and with what is it cheaper to connect a lot of HDDs to a computer?

Question

Iron

Typical situation: A lot of HDDs of various calibers (3.5", 2.5", 180–500GB) have accumulated on the farm. There is an old PC, there are only 6 SATA connectors on the motherboard. I want to make a server out of it to store movies \ games \ torrents, etc.
Tell me: how can you connect 10+ HDDs to it with the maximum budget?
Google suggests the following solutions:
- PCI expander for 4 ports (~8$)
- SATA Multiplier 1 to 5 ports (~14$)
- PCI-e x1 expander for 4 ports (~15$)
- Some 5.25 HDD RACK ( from $90) but connectors are still needed
- Server boxes for 10+ disks with controller boards (but I don't know if they will fit a regular motherboard). Yes, and probably expensive.
Maybe there is something else and I missed it?
Interested in the opinion of those people who have already done this. What are the pitfalls? How feasible? What are your use cases?
//UPD.
I will probably take PCI adapters for 4 ports. Fortunately, old motherboards have 2-4 PCI. The speed, as I understand it, will be at least 130MB / s. (and possibly 266 or even 533) Which, in principle, is tolerable, because I'm not going to stream video, but it's enough to watch a movie on one TV. Yes, and downloading torrents over a gigabit network is also enough (only in our city 100 Mbps maximum) :)

Answer 1

I'm not judging your idea, just sharing my experience.
But do you really need all these disks in constant availability to keep them in the switched on computer?
I also have archives on external drives. And I'm quite happy with connecting them, if necessary, via usb3. I use a USB docking station, which can be plugged into both 3.5 "and 2.5". True, my 2.5 "each lives in his own box. It took something - connected, read / wrote, removed.

Answer 2

PCI expander for 4 ports (~10$)

This.
Well, or buy a SATA seal (you missed it), but it will come out more expensive.

Answer 3

PCE-E take cards. Then at least the speed of access to disks will not be cut