First let me say the cost of building this is how much you want it to cost. It can cost anywhere from 125.00 up to 400.00. Everyday the cost goes up with the cost of gas so the sooner you start collecting the parts the cheaper it will be.
How much do you know about gear reduction , 100 lb per inch torque motors. You need to start looking for one that doesn't send the ferris wheel flying around too fast. You want it to turn slowly. You will need to find Two pulley's too. One about a 10" and one about a 6". It really depends on the motor you find. I would start looking for that. If you find them at the salvage yard or on Ebay you can save alot of money. The motor could cost as much as 300.00 if you aren't picky. You can get yours for 45.00- 50.00 at a salvage yard.
As for the cost the PVC pipe and connections will cost you around 25.00 and the light adapter for the lights will cost around 50.00 and you can order that thru mercotac like my wife said below.
The stand we use Two 4x4 salt treated wood posts that we put right into the ground.
The PVC fittings you should get by the bag it is cheaper that way.
You will need
32- T fittings
8-10' sections of PVC pipe 3/4"
PVC cement and cleaner. What ever color you want you will need to get the plastic fusion paint in spray cans.
Of course you will need lights.
one extension cord that you will use to plug the lights in. You will cut the male end off and wire it to the new rotating plug and attach the female end to the center rod to plug all the lights in.
Now with this said your fittings and PVC pipe will depend on how large you make it. The larger the ferris wheel the stronger the motor needs to be and the more PVC pipe and fittings you will need. Each section of our Ferris wheel is 4' and if you look at this close up of it you will see how it is put together with the fittings. notice the 45* ells(elbow fittings) and right under them is a t fitting to send the bar across the two sections. This was so I could get the two sections together. 3/4 way up the cross bars is a t-fitting to put a cross bar there in four places.
The five ways are used to hold the center rod and connect the four cross bars.
If you need more explanations post it here and I will answer all questions if I can.