Yes, it can be worth having business/jobber accounts. Availability and discounts depend on the business, requirements, and total spend per year. Get best jobber discounts on finishing supplies, and equipment. Lowest discounts on lumber, or from pure retail businesses (like Woodcraft/Rockler).
Some will not require a business account if you are consistent customer with high spend rates paying cash. I have cash jobber/contractor accounts with most finishing suppliers (SW, Mohawk, Benjamin Moore, PPG) as they require one to get discounts, and for their legal protection for proper use of solvents.
Some will not set up business account with best discounts; without a credit check (for net 30 payment terms) and sales tax exemption from local tax authority. BTW - should have a sales tax exemption certificate if you are selling your products. No reason to add local sales tax to materials cost for products you mfg and sell. Just remember to collect the sales tax on stuff you sell.
