For someone like you, sir, CMSs are the way to go.

Basically, they are no-language-knowledge required way of webmastering. Also they are able and can look fancy if needed.

If the domain name you want is acquired by someone else already, you got a) backorder b) enquiry options

Backordering is letting a certain registrar to snap the domain name as soon as it expires and is not renewed whereas enquiry is simply asking the owner of the domain about how much would he/she/they want for the domain. As you could guess the latter could prove costly. Average domain name (.com, .org, .net) is sold for around 8-10$ a year by the by. Some domains (.info) tend to go cheaper from time to time while certain ones (.be, .co.uk, .tv etc.) would cost around 20-30$ annualy. Domains are registered on a year basis.

In the scattered light of these, my recommendation package would be:

1- Grab a domain name from Godaddy.com (check retailmenot.com for discount coupons available, if any, prior to the purchase) 10$
2- Get a basic domain hosting plan ("Hatchling" has Shared SSL which is required for e-commerce) from the reliable HostGator.com for 7.16$ recurring monthly or 66.72$ for a year with coupon-applied prices (fee goes down if you make sum up payments. Also check retailmenot here too)
3- From cPanel of your adminsitration panel, get Joomla! installed in seconds and start building up your website from the sample installation.
4- If you are looking into web design combined with the functionality that meets your demands, subscribe to Joomla Club of RocketTheme (they have themes designed for e-commerce) 50$ for 60 days / 75$ for 180 days. They give technical support in their forum too.

So 10 + 67 + 50 (or 75)= 127 (or 152)$ get you a running website. * I am not sure about what being able to process credit cards on your website costs you (I think it should).

Also I don't know if you are gfx capable or not but in case you will be making logos, gifs, icons for your website, you'd need an image editor. Other fellows would fill you in better if free stuff like GIMP is skillful in editing web graphics. If not, you'd have to go industry-standard like Adobe products are. But I doubt you'd have to end up so.

Hope that helps a bit.