You want a sideline thingy generating some sideline money. You don't "need" a R250 000 site.
I can get you a fully functional ecommerce site, using free tools, within hours. Domain registration, website hosting, free ecommerce software, free template... The problem with this is that it will not feel like your website at all.
I agree - plus you can get some decent commercial templates for next to nothing, if you would rather not use a free template. It's extremely hard to start an e - commerce store and you may feel that it possibly isn't for you - this way you can upgrade the look and functionality as the business grows.
Lastly you can accept credit cards without a bank business account or number (i.e. you could use a savings account) with a payment processor such as PayFast.