how to wich one?

is there a how-to on how to use a pump? and is there any sugestions on wich pump i should get for around $30 - $40?

There is a stapled post above yours that says “Pumping 101.” Read that.

I know of no real good ones in that price range. Maybe someone here does. Minimum, you should look for one with a pressure gauge and offers different cylinder sizes.

If you are going to buy a cheap ass pump you are wasting your money. I know I have bought both.

Either spend good money and get a real high quality pump or stick to jelqing and other exercises which are also very good and free.

Trust me all those novelty pumps are crap. You will likely end up with no gains or injure your stick.

Personally I think pumping works very well, but only if you do it right and you have a good pump. Also I think you have to use exercises in combo with it to really get the good gains.