I didn’t start out with Lynxmotion stuff because I wanted to get a robot to experiment with as fast as I could so I would have something while I build a larger project long term Lynxmotion SES based project.
Now that I am pretty much finished with Octabot (as of next month, I think), I will start a new robot hopefully in January. I will be starting out by gradually getting the brackets and servos I need to build something I can work with soonest.
If I can overcome one design issue, I will be building a tri-wheeled rover next, otherwise I will be starting construction of an 6 or 8 legged walker with wheels. I have already designed these in CAD using Lynxmotion Servo Erector Set parts, so I already know what I will need for either the Hexapod or Octapod versions.
If I go with the tri-wheel rover, I will start by getting parts for one of the wheel assemblies or perhaps the chassis first (brackets, etc) then get servos as I can afford them.
if I go with the wheeled Hexapod or Octapod, I will start building legs first or maybe the wheel assemblies since I can run it as a rover before it needs to walk. I can get parts for at least a single leg per month, including servos, and can always attach the finished legs to Octabot for testing.
There are many different ways you can go when building a new project. it just depends on what you want to build. if I were building a biped, I would start out by getting parts for the legs, since you will have to order pairs of several of the parts anyways.
You just have to think about what you are wanting to build and figure out what you can get to have something actually work the fastest and work with that while getting parts for other assemblies.
You can see everything I have designed to date and what I am planning by visiting my website.
I also have several different threads here, with pictures.
The Walk 'N Roll robots will likely be a 2 to 3 year project each for me, so I will likely be doing other smaller projects concurrently with their construction.
I also want to build a “camera bot”, an autonomous camera critter for when I am making movies of my other robots.
It will be able to track another robot or other object and keep the camera on it for filming. 
I did just order all the SES brackets and servos I need to build my custom pan/tilt base for Octabot, plus 4 more sensors for it. 
8-Dale