Getting the price right is very important. You must make sure that the difference between the cost price and the selling price is enough to cover all of your operating costs, including your own drawings. However, be aware that artists can buy materials from a number of different sources, including online, and you will have to price in line with your immediate competitors unless you are targeting a niche market that your competitors do not cater for.
If you're going to sell from a shop and online think about whether you will have a two-tier pricing policy or use the same prices both in your shop and on the website. If you need to sell at lower prices online - perhaps to compete with other online retailers' prices - then think about what you will do if people come into your shop and ask to buy something at your web price.
Regular customers will appreciate the knowledgeable service that you can provide and the wide range of professional and amateur quality artists' materials that you are likely to stock. However, you don't want them coming to your shop to pick your brains and then going elsewhere to buy what they want because you have pitched your prices too high. On the other hand you don't want to set your prices too low because you may not make enough profit to keep going.
Your suppliers may include suggested retail prices in their catalogues and price lists. It is entirely up to you whether or not you stick to the suggested retail price, but if you do decide to price your stock below suggested retail prices you should keep details of your actual selling prices.
Special offers and discounts
You may well offer a discount to certain customers. For example, many artists' materials shops offer students a discount - often as much as 20% off the normal retail price. Any trade customers that you have will also expect a discount from the normal retail price, especially if they are buying in large quantities on a regular basis. The amount of discount you offer will probably depend on your pricing policy and how much local competition there is. You might also offer a small discount to members of a local art group.
You might decide to offer a price-match promise to reassure your customers that they're always getting good value when they shop with you.
Keep a close eye on any special offers you do make to be sure that they're working for you. After all, these kinds of promotion might encourage extra sales, but they'll also affect the amount of profit you make on each sale.