Hosting charges vary with the type of server you are on as well as the options the plan offers.
- Shared Server - The cost generally starts at $6 and can go as high as $50.
- VPS - The cost generally starts around $50.
- Dedicated - These can be found starting around $100, although those are bare-bones and should generally be avoided. A decent dedicated server, with full support (very important), usually starts at around $200.
All sites should have an ssl certificate. The cert that is provided with some of the payment modules is not enough. A decent 128 bit cert can be found at namecheap, and sometimes at godaddy, for $15/year. I recommend godaddy since they are now a verified ssl authority and have made improvements in their certs, but any business type cert will work. Don't be fooled into thinking the more you pay for a cert the better it is. There are some benefits to higher priced certs but, for the most part, they are just extra bells and whistles.
A private certificate requires a private IP. A host will usually charge $1 to $5 per month for that.
Most hosts offer a shared certificate you can use for free. The main difference between it and a private one is that the url will contain the name of the account it is setup for.
The payment methods available can be roughly broken down into two groups: off-site and on-site.
Off-site - These types of modules require that your customers leave your site to make the payment. The only fees associated with them is usually a per item fee. These are best suited for new shops that don't have enough sales volume to cover the costs. These include:
On-site - These types allow your customers to stay on your site while making payment. They have a per item fee, along with a monthly and sometimes yearly fee. These are better suited to sites with high-volume sales.
- Paypal Pro
If you want to pay to alter the appearance of your shop, there are two ways to do that: buy a pre-made template or have the design coded.
- Pre-Made - A popular way to alter the appearance of a shop is with pre-made templates. The cost of these usually range from $150 to $200.
- Design - These can vary greatly since the design can to but be prepared to pay from $600 to $3,000 for a site designed specifically for you.
Oscommerce is free and you are free to make whatever changes you want to it. But some shop owners don't have the experience to do that and some just don't want to. If either applies to you, then you can hire someone to do the work for you. Prices vary greatly in this situation since everyone can set their own prices. You should put together a list of what you want done and then ask for quotes from various programmers. Three or four quotes should provide an idea of what the project should cost. Please note that asking for quotes on this site is not allowed.