We do the same thing! I think ours is up to $7 million now, if you're gonna go, go big right? You only need to sell one lol. We do some work for local print companies as well and it can be a challenge getting the necessary info to make a full quotation. Alot of times we provide a $ range for install if we still are unsure about the scope. Big thing is to be specific about what you are quoting so it is easy to understand what is included and what is not and that the client understands that there might be a change moving forward. We have had the luxury of working on multiple projects with alot of our clients so our efforts to educate them about what questions to ask their customers and what info we need to provide accurate quotes have helped out alot. It's hard to make money on small, quick quotes. It's better to pad the install and not get the job then to get stuck working for free! Having a good relationship with the middle man is super important too. We had one shop who fed the end client a bunch of BS just to sell the job and we got stuck in the middle, we just don't quote for them anymore.