I am a professional artist and sell work online from my own website. It costs me £35 a year and includes use of a shopping/paypal facility. I have sold work to the USA and Europe on a fairly regular basis.
I have a package from company called Mr Site (googling should get the addy.) Very reasonable and easy...even for the PC-challenged....to get set up and designed. I had my site open for business in less than a day.
Its not a substitute for doing shows/exhibitions etc...but IMO its an essential component these days.
Please note that any unsolicited advertising will be removed