Oscilloscope (beginner) Questions

[petreza]

Hello,

I am just starting in electronics as a hobby. For now, I am not sure what kind of circuits I will be experimenting with (and hopefully one day designing), but considering that I am into programming, there might be a lot of microcontroller and even FPGA stuff.
Currently I have a soldering station and the Radio Shack's "Electronics Lab" to play with and I am about to order a quality multimeter. As far as instruments go, the next logical step should be an oscilloscope, I guess. Considering how the Rigol DS2072(A) is freely "upgradable" to 200MHz (300MHz) and the MSO/DS4014 to 500MHz, I think they present the best bang for the buck compared to the similar models of other quality manufacturers.
Right now I have the money for a Rigol DS2072(A). If I need to buy the DS4014 it would take me up to 6 months to save for the difference in price.

Here are some questions I have:

1). How much bandwidth do I need?
Everywhere I've checked it says that I need at least 5 times the bandwidth of the fastest signal I would measure. Yet, as a complete beginner I have no idea up to what MHz I would need to measure. Could you give me a list of the typical (and/or maximum) frequencies that a beginner-to-intermediate would face, (and what for). For example I checked that Arduino runs up to 20-25 MHz. Please, give me other examples.

2). I believe I would not need an oscilloscope immediately. A multimeter is good enough, right? If so, depending on your answer to the MHz question in 1), should I get a DS2072(A) - 200MHz, or is it worth saving for 6 months and getting the DS4014 - 500MHz, with the added 2 channels?

3). Similar to 2). If your answer to 2) is "no" should I save a little more to get the DS2072A-S when it comes out (assuming it is also bandwidth "upgradable"). Is the built-in function generator worth the $400 price difference or is the money better spent toward a standalone function generator like the DG4062 (which incidentally is also "upgradable"). Is there some big advantage in having the function generator built-in in the oscilloscope?
Keep in mind that as a beginner, I don't really know what a function generator is useful for.

4). Back to the DS4014 and its 2 extra channels. I found conflicting information as to the usefulness of 4 channels as opposed to 2. Some say that they cannot live without 4 channels while others say 2 is good enough. I found out that in order to decode a SPI bus I would need 4 channels and a SPI bus is something common in digital design. Then I see that if I am going to be reading digital signals, a good logic analyzer is much more useful but then if I need to time correlate the digital with the analog signals it is difficult when I have two separate instruments so that is where the MSO4014 comes in but it is $1200 more so aagrhhhhhh..... 
I would appreciate any suggestions you might have to this train of thought.

5). Any other comments you might have as far as oscilloscopes or in general?
I know I have to get (or make) a good bench power supply and read some good books on electronics.
I already have a bunch of stuff piled to TAKE IT APAAART.

Thank you all for the good advise I am sure you will give me!
Thanks to Dave and all others positing YouTube videos! I find them very interesting and inspirational.
 

[wiss]

While designing a small audio power amp resently I run into oscillation problems at some 120 MHz, a 10MHz scope would not pick that up but my 100MHz did. Just my 2c

[kg4arn]

DS2072 (A) is a great scope for the money.
Check out posts by forum member marmad for a lot of threads and info on this scope.

If I were starting out, that is the scope that I would get and save the extra money for other items (like a FLUKE 87V).
I do not have a DS2072, but I have used one briefly and there is wealth of good user feedback on this scope.

Later, as you gain more experience, you may want more channels and bandwidth; but by that time scopes will probably have a lot more "bang for buck,"  and you will have a better idea of what you need/want.  IMHO

[electronics man]

I would recommend the dds1074z it is probably the best value for money scope on the market the 4 channels is particularly useful.

[AtypicalRabbit]

I second the DS1074Z

http://www.rigolna.com/products/digital-oscilloscopes/ds1000Z/ds1074z/

Check out this thread: https://www.eevblog.com/forum/testgear/sniffing-the-rigol's-internal-i2c-bus/2685/
to see what you can "unlock" 

Most Rigol scopes can be upgraded, however any unit with an A at the end of the model # you'll need to open up and jTag to get some info from it, but that's all in the above link.