It is not hard to get your hands dirty on computer networking basics and operating networking equipment. I've been running my own home network for the past 4 years and messing around with IPv6, VLANs and multiple networks, all without expensive racked routers or switches.
The most important device you'll need is a router. Any computer with at least one Ethernet port is already a router. You can even use an old laptop as a router. (It comes with a free keyboard and mouse too!)
Alternatively, if you have an old consumer router and access point combination (wireless router) that comes from your ISP, it too can be used as an advanced router.
Usually, your computer or wireless router won't support advanced features like VLANs and have restrictive configuration options, so software is the next step in getting these devices bend to your will. There are a ton of router operating systems that you can install onto devices, or if you want to spend the extra effort, you can also use a Linux distribution.
Here's some examples of wireless router operating systems you can flash onto your router. In the process, you'll also void your warranty and may end up with a bricked device, so be careful. Sadly, some routers aren't supported by these firmwares, so when you get your next router consider checking for compatibility.
Here's some examples of computer (x86) router operating systems, beyond mainstream Linux/OpenBSD distributions
- pfSense (Very well supported, easy)
- Many more...
- Alpine Linux (For the hardcore Linux user, embedded-like)
pfSense, OpenWRT and DD-WRT come with a web user interface for easy configuration and monitoring, but if you want to take your router to the next level, you can use your favourite Linux distribution (without a desktop) and Vim/Emacs.
For wireless routers, after getting past the hard step flashing the firmware, setup is simple. Plug your WAN (from ISP/home network) into the WAN port on your router and you're done.
For computers, plug your WAN into the Ethernet port and configure it. I bought an Intel box PC from Taobao and have been using it as my main router for quite a while, it's pretty okay.
Another thing you'll definitely need to experiment with more than just one network is a network switch. For those of you using a wireless router, fortunately it comes free of charge! Based on my limited experience with wireless routers, some switches in them are reconfigurable or run in software, and those are amazing because you get to configure VLANs.
If you plan to use a computer, try to get a smart/managed switch because that will give you VLANs and other QoS management functions. I got myself a TP-LINK SG108E Easy Smart Switch via Carousell for a pretty good price ($30).
If your computer has only one Ethernet port, you can actually use a managed/smart switch to connect your computer to WAN and LANs at the same time using VLANs which is also pretty nifty.
If you need more switches, old wireless routers from Carousell or thrift shops are more value as compared to standard switches because they're mass produced more. Another side effect is you also get more Access Points to play with!
Finally, cables. My rule of thumb is: don't buy new cables in local stores. Find cables on Carousell or online shops, and if you plan to have more than five devices plugged in, you can even get yourself a reel of CAT5e cable, a crimp tool and Ethernet connectors to make your own. In my opinion it's more fun to accidentally crimp them incorrectly and watch them fail, any may even save some money if you're looking on the right websites. Beyond the cables themselves, you will also need to figure out how to run it from your ISP's terminal to your router and other devices.
With consumer routers and switches and free software, you can gain the freedom of messing with networking for a really low cost. My router box and switch cost under $200, and with pfSense running on it, I have a really configurable setup. pfSense gave me easy access to a static IPv6 range from Hurricane Electric, and makes setting up OpenVPN and port forwarding to servers easy. It also lets me run my server network separate from my home network and set up firewall rules between them.