Choosing a used carbon road frameset comes down to one practical question: does the frame line up with the brake style, wheel size, and frame size you already plan to build around? The Specialized Roubaix Comp Carbon Road Bike Frame + Carbon Fork + Headset *RARE* answers part of that question up front with a 50cm frame, 700C wheel size, and rim-brake design.
Quick Verdict
This is a frameset bundle rather than a bare frame, and the package includes more than the frame itself. The main caveat is its used history, so the decision should weigh the riding it has already seen. For a shopper with a matching size and brake style in mind, the included parts make this an interesting candidate.
Who This Frameset Suits
This frameset suits a road cyclist who already knows they want a 50cm frame and a rim-brake bike. The 700C wheel compatibility keeps it within a common road wheel standard, and the headset and seatpost clamp reduce the list of extra parts you need to source. If you already have 700C rim-brake components, this becomes a more direct fit.
What Stands Out from the Title
The *RARE* tag in the product title adds a bit of uniqueness, and the package stands out because it includes the structural pieces that are often separate purchases. Those pieces being together makes the frameset more complete. That is a practical advantage when you are starting a new build.
SPECIALIZED® ROUBAIX COMP Carbon Road Bike Frame + Carbon Fork + Headset *RARE*

Choose this Specialized Roubaix Comp Carbon frameset for the completeness: the carbon frame arrives with a full carbon fork, an FSA carbon headset, and a seatpost clamp. The limitation is the used condition. It is in Good Condition with cosmetic scuffs and wear marks, so the finish will already show riding history. At USD 395.00, the price balances the included parts against that visible wear.
Bottom Line
At USD 395.00, this Specialized Roubaix Comp Carbon frameset is a coherent starting point for the right road build. The included fork and headset simplify the early steps, and the main remaining question is whether the frame's size and brake style line up with your parts. If they do, the bundle gives you a clear path forward.