So you know that if you're hosting WordPress. And you want to really speed and security. WP engine and Page.ly both outstanding WordPress only hosts that are extremely fast then built to be quick and safe. Offer discounts to SEOmoz pro members
Pagely offers 30% Off All Plans for life. That would bring your total under $20.
https://page.ly/
The WP engine offers 4 months of free hosting. If you take that into consideration it is less money than obviously paying for its full price.
http://wpengine.com/
These are each managed and extremely great companies to work with.
Just for informational reasons and because I think you should know
ZippyKid offers you an enterprise class DNS system and content delivery network
For $25 a month it is a WordPress only site like the others. However it too offers incredible speed and customer support.
https://www.zippykid.com/
Web synthesis is 8 web hosting company built for managed WordPress again however they like the others are outstanding security as far as speed and support. I felt you should know these at least exist.
http://websynthesis.com/
Lastly page fully keeps giving you 30% off every new account you add and they're backed by fire host which is a 100% enterprise host.
Zippy kid charges $15 more per a site or $10 more per hundred thousand views per month
WP engine goes up to a much higher plan that would equal $10 a website if you were running all WordPress. It would be a good choice.
Web synthesis is $200 for no more than 3 domains so you don't save a lot of money adding sites. However they're very very good
here is the link you need to find the discounts through SEOmoz
http://www.seomoz.org/pro-perks
So you know these sites are going as far fixing that work hacked site's that was attacked for free and giving you a lot more than what you actually get by paying it to each different vendor to make a host like this.
Content delivery networks and any cast DNS make your website very fast along with private clouds and top tier data centers that's where the true speed comes in and I would suggest if it's WordPress one of these.
Again I understand you set under $20 and I do believe page.ly we now meets that criteria I don't know if you are going to use it for WordPress were not but if you are I would recommend using one of these.
So you know as well if it's not WordPress that's fine of course**, then** I would use pair networks and I would add either MAX CDN or CDN77 each content delivery network costs under $39 for 1 terabyte that's much more than many websites will ever use in a year. This will add speed to any of your sites you can also use a company like DNS made easy to get 10 domains hosted on their anycast DNS network with 11 year uptime
http://dnsmadeeasy.com
With Pair http://news.netcraft.com/archives/category/performance/
I should also tell you SEOmoz perks gives you great deals on domains
If you need a name that is registered or very unique http://www.dynadot.com/ is the place to go a nother that seomoz made a deal me to deal with with is http://www.namecheap.com/
http://www.singlehop.com/partners/reseller-hosting/#white-label
Free reselling from Singlehop, Pair & Page.ly
I hope this was of help,
Tom