I should mention with the Asus routers in AP mode they also.work as a 4 port gigabit switch. Depending on locations that could make hooking up 8 devices an option.
In most cases that probably isn't going to work unless the devices are fairly close and you have a way to route the wires or can deal with exposed wires.
Here's an affordable semi-managed switch I'd recommend, it's a
Netgear with a Lifetime warranty. They're excellent units and on sale for $99, and can even do some QoS, VLANs, SNMP, etc.
The
Ubiquity Switches run more, but for good reason as they are good switches and are a solid value. Though unless you need more advanced networking configurations or are doing a lot of larger data transfers that require stronger bandwidth control, I think it's really more than you need. If you feel you'll modify the network or go beyond the basic VLanning and QoS that the Netgear above can do, then by all means this is a great next step before the $500+ Cisco's, HP/Aruba's, etc.
The
Edgerouter Lite3 is around $90, and is worth it. I have one as a spare. The 1.90 firmware is solid and if you're willing to do a little command line and follow some of the many good guides, this is an easy router to setup and is very effective.
I linked the Asus RT68U above for
$59, it's a
$150 home-grade router that claims to cover 3,000sq feet, and after conversion is a more friendly and easy-to-work AsusWRT UI and with Merlin is pretty effective and fairly decent for home-use. Though there's also a
$50 UBNT EdgeRouterX, that many users like and is a solid device if you are going to have a simple network on a budget. Great little performer and in some cases can be a little faster the the Lite, just not as resilient overall and will struggle more if you have more high bandwidth transfers and features enabled.
If your'e going AP's, that's a tough go. A couple RT68U's will do pretty well and give you AC bandwidth for an amazing price... the
Ubiquity AC Lite for $75 is the next best, and probably has the same range. Both should easily handle your wireless load. The AC68U has an 800MHz overclockable dual core, and MerlinWRT is modded AsusWRT and both are very stable. Ubiquity is pretty stable too, and there's more setup options if you want to run multiple SSID's. While you can do this on both, Ubiquity does it better IMHO.
The better option, the
AC Pro is a beast for $130, I've deployed so many of these. Really I go for Ubiquity at budget locations and Ruckus for enterprise-grade. That's a $500+ AP though. Should speak about how well we like and trust Ubiquity wireless products, the AP's have been pretty solid overall and Ubiquity's been really good about keeping stable firmware releases coming.
A couple of any of the above should really do you just fine, the Asus routers should even perform pretty well in that environment. If you did 3 using one as a wireless router and two as AP's, you could probably do just fine coverage-wise for the cost about $40 more than one AC Pro AP. BUT, in the same breath as
@Solaris17 correctly put it, Ubiquity is prosumer. They are overall better products, meant for set-it-and-forget-it and more advanced network management capabilities. They will handle more and be more reliable in the long run. Again, depends on budgets and needs. It also depends on skills because you don't want to necessarily use the TMobil firmware on the Asus routers, but rather do the conversion process which requires using SSL or Telnet for some CLI action...though its not hard, and with patience will be just fine. Plus I could help walk you through it if needed along with other users here that purchased those same devices.
I agree with SophosUTM as well, pretty solid along with PFSense for being options if you build a small PC or re-use an old PC and add a second NIC or a dual-port Intel NIC (I find em on Ebay for $30 shipped for Intel Pro PCIe). I actually retired my ERL for PFSense, while I enjoyed the ERL and it's CLI, PFSense made more sense (lol)...and has a lot more capabilities in the GUI, a lot of options and when you mix in things like Hardware accelerated OpenVPN servers, Squid Proxy/Cache, Snort IDS/IPS, bandwidth monitoring, advanced QoS, better multi-wan support and failover, and faster and more frequent upgrades (could be considered good or bad), I feel PFSense is a better platform for using more advanced features. I also prefer its firewall capabilities and rulesets...its like a happy medium between EdgeOS on the ERL and SonicWall SonicOS. IMHO.
I built a PFSense box for around $250 with shipping spring 2016. I used an Asus N3150-C with a quad core Celeron SoC passively cooled as the core, a dual port Intel Pro gigabit NIC (as PFSense didn't recognize the Realtek onboard NIC, I expected this going into it), 8GB RAM, 120GB SSD, mITX case with SFX PSU. Has been one amazing build that I'm running all the features I stated above that PFSense can do. Mostly for lab, testing, and experience. It has been an amazing build though and its one helluva router. I do keep the ERL around and fire it up to update it and update the config so I can drop it in should my PFSense box ever give up the ghost. There have been folks that have build solid PFSense builds for closer to $150.
Homebuilt routers are capable of better performance when built and configured correctly.
There's a lot of ways this could go, it depends on what you want, what your experience level is, how much you want to pay, how much you want to learn to make it all work, your concept of networking, etc. Hopefully this post is useful in realizing those to make your decisions so you spend your money wisely.