@paddedhat
Thank you very much! In general, are the local suppliers reluctant to deal with DIY folks?
When I was in the HVAC biz, there were a number of suppliers that simply wouldn't do business with you if you weren't "in the trade".
Can you recommend some online vendors for PEX?
Suppliers, and their relationship with the walk-in trade and DIYers, is something that you can't really make a blanket statement about. Some are fantastic to deal with, some have a sign on the door that literally says "go away". For a supply house, the "value" of doing business with homeowners, and DIYers is pretty interesting. My local electrical distributor is an example. When it was locally owned, management had a community minded attitude, and felt that it was important to be there on Saturdays for the guy that needed help running power to his shed, or finding a new bulb for the aquarium light. The new owners decided that if they couldn't generate X amount of sales that day, they were probably spending money to stay open, and they now operate from 7-4, weekdays. Anybody is welcome, but the contractors keep the doors open, so the hours are set for them. Generally, I have found that the availability of the big boxes has changed the game. Many supply houses that would avoid DIYers in the past are now not only will to do business, but willing to be pretty competitive. I would recommend that in dealing with them, you keep the purchases large, and you let them know that you are serious. For example, don't stop in the local lumberyard, tell them you are flipping a house and want "contractor prices" first, the guy you want is probably in a dumpy back office, and is their "outside sales guy". Chances are, he is not working the counter, and showing little old ladies where the Elmer's glue is. Secondly, the counter has seen hundreds of idiots come and go, idiots who were going to be the next big time flipper, contractor, etc... Get a printed quote from a big box store, use a piece of scrap paper to block the $ amounts, and make a copy. Ask who you can give a list to, since you need a quote, and it's a cash quote, paid in full before delivery.
Finally, there are always going to be supply houses run by total a-holes. IMHO, at least in these parts, these a-holes seem to gravitate toward the plumbing/HVAC area. There is one here that has an amazing culture of arrogance and distain for anybody that isn't part of their little club of contractors. I simply won't walk in the door there anymore. It's so bad that a very large friend of mine actually jump the counter, and offered to do some attitude adjustments, as a counter guy was running away. The other extreme is the houses that are just idiots who have the idea that if you aren't going to spend several thousand a month, they will be happy to take your money, IF you pay full retail. I have a great supplier for tubs and showers. The unit I wanted was out of stock, and I called a nearly competitor to see if they had one. They had it in stock and wanted almost twice the price. I asked if they would do better since I typically pay about half that? The logic of what came next is why you sometimes have to shake you head and walk away. They told me that they can sell it for that price, "once you become a high volume customer, and you buy ten tubs or so, then you would start seeing prices like that". I replied, "no, that doesn't work for me. The guy up the street usually stocks what I need, and welcomes my cash, I'll wait"
As for the PEX question, I've had great local access, so I can't really recommend an online supplier.