Finding a Hoster
If you have your own domain name, changing the company that hosts your web page is not a big problem, since it will be transparent for your visitors, and they still use the same domain name to go to your shop.

Stages:
Phase 1: As cheap as possible, but reliable
In the beginning when you don't have a lot of visitors you can go with a cheap hosting company. It should not cost you more than 15$ per year to get this done. Usually you get about 5MB web space with the package. If you need more than 5MB, have a good look at your images and make sure, they are not too big. 5MB go a long way for a new page.
You should however look at a few points even with a cheap web-host:
- Do they have a lot of down time? Ask for availability if you are not sure, or they don't have any information on their page.
- Only go for "banner less" hosting, which means that the hosting company cannot place any banners on your page. It should be up to you, if you decide to place banners yourself.
- What happens, if you get more visitors? Make sure, they give you a warning, if you use up too much bandwidth, and not just close the page and block your visitors.
- Make sure, you have FTP access to update your page.
- Email forwarding should be standard. You should be able to define rules for email forwarding, for example: anything@yourdomain.com gets automatically forwarded to your hotmail or yahoo address.
- A pop-mailbox is a nice option but not a "must".

Phase 2: More visitors - high bandwidth and/or high scripting
Once you have a certain amount of visitors, your web hosting company will contact you and tell you, that you need to upgrade your account. In general: You get what you pay for.
I have had HUGE trouble with a cheap hoster (Alfahosting.de), which promised to host one of my high-volume web pages for 150$/year. This page had about 2GB traffic per day, and I thought I'd make a killing with that deal. What happened was, that the hoster could not cope with the traffic after all and shut the page down.
Other hosters are more expensive, but also more reliable.
Most of my pages are hosted at http://pair.com (see also the "links" section). For a page with about 3,000 visitors per day I paid about 30$/month at pair.com. Again: I'm sure, there are better deals and even better hosting companies out there. I'm just telling you here what my experience is, and I can tell you that this is a good option, since I dealt with these guys for more than five years now.