Micro lens for nikon?

I went to a camera shop and was told to get a micro lens for close up pictures (flowers, bugs ect.) but being only 16 I can't afford the ones they recommend ($1000-$2000) are there any good ones that are under $500?
I have a nikon d5100

I was thinking about the Nikon AF-S DX Micro-NIKKOR 40mm
Is this one good?

The 40 mm lens is perfect for what you want to do.

ALL real macro lenses (not zoom lenses that say they are macro lenses) are excellent.

Well, the 40mm Micro Nikkor can be good for flowers, maybe. Working distance is short, so it won't be good for live insects. I hope that you already have a good external flash. A special macro flash is ideal, but a general use flash like an SB700 used as bounce flash can work well. You still need a good tripod with plenty of adjustability, even with flash to freeze motion. Depth of field is shallow at such short distances, and fore-aft swaying can make it hard to ambush an accurate focus.

The 40mm is a good starter lens for macro use. However, you may find that you have to get too close to photograph bugs. Flowers or other inanimate objects are fine. Or if a bug is on a push pin.

Save your money and wait for tamron 90/2,8 - tamron 90/2,8VC sigma 105/2,8os… Or buy some old 50mm prime lens and cheap extension tubes, same results as 40micro but less expensive ( about 50$ )

I use a Tamron 90mm and sometimes throw a X2 converter on it to give me 1.1… It works great for me.

Just a quick bit of advice… When shooting nature and wildlife shots up close with a macro lens… It can be difficult to get good results to begin with… A gentle breeze can be really annoying when you are trying to capture that Dragonfly or Butterfly that's posing nicely on a single blade of grass… It takes time to develop the right level of patience and technique to get good results… Don't be put off… It's very enjoyable when you get nice shots… And one last thing… Sometimes the insects like to check you out… It's something you have to get used to… I normally go for a trek early in the morning when insects can be quite aggressive and then turn around and head for home just around lunchtime… It's on the return leg I start to shoot… I cover between 15-20 miles on a trek, sometimes more and it's in forest terrain… It can be quite an experience and you need to be able to keep a cool head.