Looking around and found 4 different modern Omega watches that I like the most (out of many).
You have selected quite a diverse group of watches as far as function and appearance. The only common element is that they're all Omega.
--> 3 of 4 have a a white dial with blue index markers - this is a rather uncommon aesthetic that you are clearly drawn to
--> 3 of 4 are chronographs with 3 subdials - you either need a chrono or like to look of such a dial
--> 2 of 4 are intended for water, but it doesn't seem you're looking for a "dive" watch so seems water-proof'ness is not a primary concern
For me, there are 5 major 'dimensions' I consider when looking for a watch:
1. Age (whether new from an OB or AD, new from 'grey seller', used but recent model, vintage) - Your choices suggest you like recent models but not necessarily new or current offerings at the OB/AD. This is something everyone has to decide for themselves. I always prefer a new or very recent model, but there are many on this forum that are opposite and only like vintage pieces. Only you can decide.
2. Function (whether Diver, chrono, GMT, simple 3 hander, day/date, moonphase) - You appear to favour a chrono. This is the most flexible option in my view as many of us tend to end up with more than 1 watch and so it's possible to start with the model we need/want most and then add other functions later as we add pieces in our collection. It sounds like you're looking for your first and/or main piece and I would strongly suggest you go with a chrono based on the options you showed.
3. Appearance (colours, style) - You are clearly drawn to the white/blue combination and 3 subdial layout. This is a very personal thing as what one person loves another hates and vice versa. You love the blue/white, so go with it. Many people are drawn to black dial watches in the 'tool watch' area (ie: black dials dominate the Rolex line-up...) but you should buy what looks good to you. Others will only spot what is on your wrist occasionally and most people you meet won't even notice what you're wearing, you however, will look at it many times a day so it needs to look great to you and only you.
4. Brand - here you've clearly chosen Omega. It's a solid brand with strong reputation and this is the OMEGA Forum after all.
5. Material (steel, gold, rose gold, titanium, platinum) - Here you seem good with steel.[/QUOTE]
... would like to know which one would you recommend
Based on what I've written above, I would recommend #1 for you. It ticks all your boxes, it looks great and it's reliable with good water proof'ness.
...and what would be considered a best buy of sorts.
A watch is not an investment, it's a luxury good with a secondary benefit of providing some basic functions. You have to choose the watch
you want and then buy accordingly.
...What would be fair price for each?
When I've selected a watch Iwant, I take months in researching and frequently checking this Forums sales area (and similar related forums), ebay, Jomashop, Watchrecon, chrono24 and also OB/AD's. For me, I feel that only I can decide what is a "fair price" when it is my money I'm spending. Your preferred appearance is not the most common and therefore the number of watches available will be lower than some others.
Patience is important if you want to end up with a good deal.
Finally, enjoy the research phase. It can be a lot of fun and it's the least expensive part of this hobby!