A needle valve and a solenoid need not necessarily cost $70. You can probably pick up a solenoid for $15, and bargain hunt for a cheap needle valve.
Another thing to consider is that the first link has a Milwaukee regulator. Some people have had bad experiences with the Milwaukee, while others have had no problems with it. The second link has a Cornelius regulator, which is more reliable, in my opinion.
The second one has what appears to be a 10 pound tank too, much better than a 5 pound tank. If you are willing and able to take the time and trouble to search out and assemble all of the parts, you can very likely beat either price by doing so, and have a much better quality assembly.