By far the best place to find good deals is LowEndTalk.com or LowEndBox.com (they’re pretty much the same site, LET is just a forum-based version of it, you can generally find better deals on LET if you’re willing to look around a little bit).
I’ve used a few different providers from LET over the years, the ones that I can personally recommend would be Advin Servers, Layer, RackNerd, BuyVM, Crunchbits & Hostbrrr. There’s probably a few more that I’m forgetting, haha, as I have used a lot of different companies which were promoting good deals on there.
You can easily find a deal on LET (especially if you are willing to do something where you pay for 3, 6, 12 months in advance) for a VPS and get your price WAY under $5 a month for running SlickStack.