Is it worth buying these macro filters (nikon)?

I've just bought my first dslr - nikon d3100. I'm pretty familiar with all the features in the camera body but I'm don't know much about the lenses. I like taking macro photos and the question is: Is it a good idea to buy these

http://www.ebay.co.uk/...0632989126

By the way, I'm completely out of budget and I still need to buy a case and a better SD card. If you have any suggestions on these, please tell me.

They 'll work, but don't expect high quality results. Best results are achieved by using a (pricey) dedicated macro lens of course, but in a pinch you can use a good close-up filter which usually cost GBP 60 or more. Since you usually get what you pay for, I'm not too sure about the macro filters you mention.

Alternatively, you could use Nikon-fit macro extension tubes, which IMHO give the best result because you don't add to or alter the original optical characteristics of your lens, just lengthen the distance between the lens and your sensor using a hollow extension tube. However, using macro extension tubes means that you'll lose all auto-functions such as auto-focus and metering, so you'll have to rely on your mastery of manual photography.

I purchased similar macro filters and was happy with the results.
However after I purchased extension tubes for around the same price, I never used the filters again.

Macro filters in general are not worth what you pay for. The only exception is the Canon 500D macro filters (which will work on any brand camera). However, they are not cheap ($150).

Basically, you get what you pay for.

The other choice yo have, and probably the best bet for getting into macro inexpensively is a set of Kenko extension tubes. There are two versions of extension tubes; manual and electric. The manual tubes - that usually cost $20 do not have any electrical contacts, so you need an AF-D lens to adjust the aperture, and you need to be on fully manual (manual exposure, manual focus).

AF-D lenses have the aperture ring on the lens so that you can manually adjust the lens aperture. This is required for the cheap extension tubes.

The electrical versions have electrical contacts for the lens and typically exposure and autofocus are maintained. But they cost about $200 (which might be cheaper if you don't have to buy a AF-D lens).

Also, make sure you get the extension tubes for macro use, and not a teleconverter (they look similar).