Diesel fuel shut off selenoid/relay. What's the right price?

I have a 1996 Dodge Diesel 3500. The Diesel fuel shut off solenoid/relay is bad. Local dealer wants just over $1000.00 (their mechanic strongly sujested replacing both) I found a couple local shops in the $500 to $600 range. Instillation is a small part of that at $100. Then I look on line: I find a solenoid from Summit Racing for $260, and then I found others; at just about any price point all the way down to $39. (the cheaper ones coming out of china) and some of those were $150 +. So where do I buy one ? and not get junk. And is the $39 junk as the $150 junk ? They all have money back guarantees. Any thoughts ??
Thanks
GarB

It can be a crap shoot sometimes. As to parts procurement, a shop may not (and should not actually) get involved in installing parts provided by a customer as that can lead to problems due to inferior parts and it also affects their bottom line by eliminating any parts markup.

Money back guarantee would apply to parts; not to labor if by some chance the part was faulty or failed soon after installation.

My preference is to buy parts locally from a brick and mortar store whenever possible. That way if there’s a problem with the part any return is made much easier.