Flaky Wi-Fi? You may not have to buy new equipment; just tweak your existing set-up.
Let's explode a major misconception first: buying a new router with fancy new wireless technology won't necessarily get you better speeds. Whatever equipment is connecting to, it also needs to support that fancy new wireless technology, effectively eliminating most smartphones, consoles, media streamers and a good swathe of laptops, too. If your phone only supports 802.11b/g, then 802.11ac ain't gonna help you much.
It's also worth ignoring the big number on the box. No single client will ever see the advertised 300/450/600/750/900/1300Mbps, as that's the total capacity of the router for all connected devices. Actual speed per device will vary massively, depending on the environment, capability of the wireless receiver and antenna configuration inside the device. To give you an idea of best-case scenario, the fastest speeds we've measured on 802.11n 2.4GHz, 802.11n 5GHz and 802.11ac 5GHz are 139Mbps, 205Mbps and 537Mbps, respectively. 802.11ac is awe inspiring, but barely anything is available yet that can actually receive that signal.
So, let's see how you can improve your current situation with minimum spend.