macro filter would be something like Raynox DCR-250 I believe, it attaches to the front of the lens.

a macro extension tube on the other hand, is placed between the lens and the camera body.

unlike macro filter, extension tube doesnt have any glasses

filter degrades the quality of pics
it lil sharp on centres and worst at corners

here is image i took using 10x hoya filter

I own 100mm macro, but most of the time the subject is to small. The raynox help reducing the minimun focus distance for more magnification. For me, I no longer use the ET as high chances dust get into the sensor. My fav combo however m43 body, olympus 40-150mm + raynox. Its light, cheap combo and importantly still do the job.

nope.
any additional glass, especially the low quality glass will degrade ur photo quality. usually it'll decrease the sharpness and contribute to more CA.

ext tube doesnt have glass, so no changes in the photo quality.

still, macro filter is much more easier to be used compared to ext tube

some samples. taken with 50mm + ext tube:

sure can crop, but it will be different story, the quality will not be the same

i taken few photos of ants and flowers before, quality not really that great, raynox will do better job i guess

100mm with raynox 250

yeah 100mm L macro
i also add ET for normal shot .. only use raynox for close up, or very small insect

without raynox

with raynox

daniel, if you don't already know, macro lens can be used as a normal lens like any other prime lens to focus on everyday subject, just that macro lens allow you to get very close to the subject. if you're really interested in macro, straight get the macro lens. macro lens usually have higher optic quality, but with smaller aperture and longer focal length.

for E mount version, 30mm isn't very long but still not very convenient as multipurpose lens. but if that's what you want, it's better than spending extra money to try all sorts of macro lens alternatives to end up giving up and buy the macro lens.

that lens is 45mm equivalent, while lumia 800 is 28mm equivalent, which is about 1.6x of lumia 800. you can always try setting your phone to 1.6x and see if you like the field of view.

it is a true 30mm, but on a smaller sensor compared to full frame, you get smaller crop. to get the same field of view in full frame (35mm format), it's 1.5x of aps-c, which is 45mm. so people use the full frame 35mm format as the standard for equivalent. like Nokia 808 actual focal length is 8mm, but to make it equal to 35mm format for easier interpretation, it's actually 26mm.
save money. it's interchangeable lens camera, you'll start to invest quite a few more lens in the future.

I am still a noob in macro

But macro lenses will allow you to get much closer for smaller insects, and should focus better and easier too (Assuming you are using an NEX-3N + Kitlens at the moment) 
Summore macro lenses can be used for normal shots too, although they in general focus slower than prime or kitlens   

A quick Google search revealed that the 30mm macro lens doesn't seem to be very good at optical quality, especially soft at the corners 
But can't really expect too much since its pretty affordable 

i mean, save more money and top up for the macro lens along with the kit lens package.

or, save up for adaptor and macro lens from other manufacturer. the good thing about the NEX is the focus peaking is dead easy to use.

2nd part of your post, it really depends on the optical quality of the lens, the better the quality, the higher the price. so the SEL30M priced at RM999 retail, i wouldn't expect too much quality though it should be better than the kit lens. i never try the macro lens, only playing with demo unit at KLCC. phone them and see if they have SEL30M for demo, and bring along your SD card.

Wah, a bit hard to compare there since both are different type of lenses man
Personally I think soft corners may be a problem for macro since you don't always frame your subjects in the middle right? 

As for the features, no worries, they will be around even if you switch lenses 

RM2k is pretty good already yo

Can get either NEX-3N + kitlens + a fancier lens; or even a NEX-5R + kitlens
I would recommend going for the NEX-5R instead, better ergonomics and controls

That extra dial on the upper right will help a lot in getting you the settings you want as compared to none on the NEX-3n
Definitely worth it 

Not to mention you get touchscreen for easier access to functions etc.

Not sure how much the NEX-5R costs now that the NEX-5T (~RM1950 with kitlens) is out.
But do expect the price to be cheaper. Since the NEX-5T doesn't really have much upgrades from the 5R, the 5R is the better pick, especially if you are on a budget 

I think you should stick to the kitlens (I don't think they sell NEX body only), and invest in some cheap extension tubes. That should be within your budget
Play around with it first, when you are familiar with macro already and when budget permits, then get a dedicated macro lens 

that seems always a common dilemma for first camera.

like myself, when i read more about cameras, the more i "want", and end up no decision. so i went and bought my first camera and learned a lot since then.

Daniel you need lens longer than 50mm otherwise you'll vignetting which is not fun if you considering raynox. Anyway looking at your flickr, I feel shame cos you have been taking wonderful photo just with HP hehe..

part of the attributes of a good macro is it is capable of maintaining a very flat focal plane.. how else did they do photo reproduction then?  Nikkor 50 is reputed to be among the favorite..  so to accept soft edge is not relevant.  IF you use stock prime for macro work then it will be soft because it is not design and compensated to have a flat surface edge to edge. There are sweet spots you have to use to achieve those results... refer to each lens technical datasheet for them.  Have fun...  BtW,, enlarger lens do make good macro too...