(Suggestion Appreciated) Vintage Omega Newb

Hi All
Appreciate having a place like omega forum where new vintage watch collectors can join and learn without paying too much “tuition”
I am new to omega vintage world and have a few question that I would like to ask and hope it’s useful for other new joiners as well
1) is there any good book(s) on vintage omega that you would recommend which gives reference information on model/dial/case/material/manufacturing volume….etc variation information. And if comment on collectibility/market price would be even better.
2) I am looking into different sources for my first watch (now am actively looking for 101.009 and c shape constellation) however I am quite confused on the price as it varied substantially. The only good reference I have would be the Christies auction sales record, however condition report is always vague. I am willing to pay reasonable premium for great condition and reliable seller however also don’t want to overpay. Any suggestion on price reference and price negotiation suggestion (dos and don’t)
3) Gold or Steel. On Chrono24 I saw some good condition one in gold (guess the great steel version would be more popular and seldom “stay” on shelf?) but hardly see the steel one in great condition. Does that mean gold is less desirable? And what’s the approximate price variation if the case is steel, gold plated, or solid gold.

thank you in advance of any feedback provided

I think the best answer for all three of your questions is Omega Forum. This site has a plethora of information for what you're looking for in terms of references etc. It also has a plethora of experts who will help you if you show that you're putting in the legwork. As for prices take a look at sold listings for c-cases on the private listings as it can be a good starting point. These will provide you honest examples sold at honest prices from honest sellers who aren't looking to rip you off. Take your time to look around and utilize the search function on OF. As for the final question, that is your preference. I personally enjoy SS.

Best advice I say over and over is do your research before a purchase. Understand what you're buying before buying. Good luck and welcome!

Just bought myself a reference book hope it helps