I've been buying from Grainger as a walk in customer for about 5 years. They're the least hassle to buy HVAC parts from locally, most places here are repair businesses that won't sell parts unless they're getting labor too, or are mom n pop suppliers to the local repair shops and won't sell to the public. At first, the counter guy at Grainger was ringing it under the local navy base account, paid at purchase of course and full retail price. Then about a year ago one of them asked if I had any family members whose business may have an account, which worked and I still pay at purchase but get the business pricing.
Always dealt with the same three people there, and they've always been pleasant to work with. Most of the time I come in with the p/n's I need, but once or twice they've had to look something up for me and have been nothing but helpful. I always end up lusting after the tools while I'm there, but the markup is too high on those! I can wait a few days for tool purchases online, but when the air conditioner goes out and it's 95 degrees I'll pay a premium to get it done today [emoji1]