Should I buy this? Fuel cell

Is $70 a decent price for a fuel cell for a challenge car?

https://www.facebook.com/marketplace/item/1066564924507276/?mibextid=dXMIcH

Not a bad price. The "half full of foam", would concern me. I have seen old fuel cell foam start to  deteriorate and cause all kinds of cool problems. Recommend removing and cleaning the cell and either using without or installing new. Depends on what You plan to do with the car. 

I don't like the foam, I don't think it holds up well.

I used a 4 gallon vertical type with tapered bottom.

What kind of capacity do you need?

You will likely want to change the cap on any cheap cell to a billet piece.

For a larger capacity I would run a surge tank so the high pressure pump cannot get air.

Be sure to run a screen before the pump to keep the foam out.

If you must run foam keep it fresh. (6 months?)

I prefer a poly cell as it will not rip a seam if hit.

https://www.summitracing.com/parts/sum-290110

Need more fuel, put in 2. (ouch! the price doubled since I bought one)

That tank is looking better. You can add a cheap Ebay surge tank.

Or you can anchor the pump in the tank with a Fuel Mat.

For racing I would want an external pump for ease of service.

It's for the C3 Challenge build over on the Builds forum. Autocross and maybe some track days.

If You buy it get rid of the current foam. I pit for a friend with a dirt track modified. Friday night he said the engine "stumbled" but then cleared up and ran ok. We finished second by 7/10th of a second.  Saturday before the race I changed the fuel filter and found fuel cell foam in the filter. I asked the driver/owner how old the foam was. His answer, "I don't know". Wrong answer. Correct answer, " Too damn." We won Saturday night.