PVC as the frame or the mold? Yes PVC for the mold will work that's what most of us use and the expensive cheese presses sold on the internet use that as well.
Just go to Orchard Supply Hardware if you have one or any hardware store that sells cut lengths of 4" PVC. You can also try plumbing and irrigation supply, just call on the phone and say you have home project or something and that you were wondering if they had any remenants they would sell or something to that effect. It shouldn't cost more than $5-$8 a foot. You need 4" PVC, the inside is 4", and 8" high. Then get yourself or borough a 4" hold saw and drill press. Then goto Tap Plastics and get a piece of their cutting board material or HDPE (High Density Polyethelene), they might have a scrap piece as well. You need about 5" x 5" piece of HDPE x 1/4" thick. That shoud cost about $2-$3. Then clamp at the edges the piece of HDPE on your drill press and use your hole saw without the center drill bit, you don't want hole in the center. Then go slow and cut through it, you will want to put a piece of scrap wood underneath so as to not mar the surface of the drill press. If you don't have those tool call around to local city colleges and see if you can use one during class, I'm sure they'd be more than helpful. After you cut the circle use some 100 grit sandpaper on a hard sanding block and sand the edges until it goes into the PVC pipe. Too loose is bad you can make it so it take a little force to push the disc through the pipe, a litte force not tons. Also while you're at Tap Plastic get some more cutting board material 1/2" thick x 6" x 6" about $6-$7. Then draw lines with a square every 1/2" then turn the board 90 degrees and mark every 1/2" on every other line, so the where cross hairs are, are staggard not in a row, although it really doesnt make a difference. Then using a drill press or hand drill use nothing bigger than 1/16" drill bit drill the holes out. Then screw 6 rubber feet onto the bottom. One in each corner and two near the center, so the board doesn't flex in the center when weight is on it. You might want to put some 1/16" holes staggared on the PVC pipe as well, go all the way up so when you flip the cheese you just flip the entire mold. Now you're done. So after sterilizing this whole contraption, you can use the dishwasher without a drying cycle with soap, just for the first time to degrease the unit, then once with no soap and no heat cycle to get everything off it, then you're ready to use it.
With this unit you really don't need to use cheese cloth, I don't. Ladle your curds into the mold put the follower in and then use a smaller piece of pipe 3" in diamter or so anything wide enough to be steady and then put some weight on it, be creative. Now that's an easy mold, but I gave you dimentions on the parts to be able to modify it at a later date if you want to upgrade. Personally I don't like the cheese presses that use springs, they're not calibrated and don't have enough force to account for all pressure ranges. It's best to stick with the weights.