^^ thats a nice tester with the hand pump, good job reps given.
this is a very easy way to build one from homedepot for about 12-20 bucks depending on what you buy
you need to go to the sprinkler section and find these pieces
1) 1/2" tee
2) 1/2" male end with 1/2" female threads
3) some 1/2" inside dia beer bong hose (only need a foot off the reel)
4) a 1-100 psi gauge, (find them by the toilets)
5) one 3/4" hose clamp for the gauge, put a little bit of super glue on each fitting so your sure they wont leak before you hose clamp them down
6) the correct PVC fitting for the intake boot, if you have a stock boot its the 1" x 1/2" female threads, if you have 30-38mm its the 1-1/4" x 1/2" female threads. make sure you have the right size by screwing #2 part into the PVC intake boot fitting
7) the easiest way to block your exhaust port up is to use the correct size expanding plug
8) a valve stem from an old tire or go to a tire shop they will give you one for free, trim the sides down with scissors until it fits in the beer bong tube snug, also use super glue before you clamp it
you should end up with this.. there are many different ways to build one and once you understand the process, you will see that "its not rocket science"