While it's definitely not super cheap for older systems (though you can easily get a PS1 and N64 for about $10, and the PS2, Xbox, and GC are all falling in price too), emulation is a less than perfect solution for most systems. While it's a great way to test games before splurging on them, usually the sound and/or the picture is off. Plus there's always something to be said for taking a game, putting it in your console, turning it on, and instantly playing, without having to wait 45 minutes for Wolfenstein to install on your hard drive.
I too would rather have all original hardware, and I do. That part isn't as bad yet. Systems tend to be still fairly reasonably priced. But games is where the downfall lies. Some games are just insanely priced. If you don't go with emulation, which is not as bad as some make it out to be, I'd certainly suggest any console you get that you also modchip it or get a flash cartridge. Whichever is applicable. Little Samson for example is a fine game worth playing. But is it worth $300+ to play it? Hell no.
You can easily get a PS1 for $10. You can't get a N64 for $10 unless you get lucky. Regular asking price is about $30 WITHOUT controller. I wouldn't recommend jumping into collecting for that yet, unless you've a few games here and there. Focus on your SNES, Genesis, and NES. They easily provide more hours of enjoyment.
Oh god. The US is **** flooded with N64s. Stupid how much people ask for them, over 1000 units on ebay at any moment.
I know. It's ridiculous to want more than $20 for a complete system if the library of games isn't even that big.
And that's just counting one website in a single country, used only. Didn't include new. Even I have three of the main unit. (but two have been cut to fit Japanese games)
I have 2 of them. One of them is RGB modded and has the tabs cut, the other one is stock. I also have quite a few games. I was lucky in that I started collecting for the N64 long before the prices started to rise. I made a thread about my collection a while back: http://www.assemblergames.com/forums/showthread.php?51495-la-li-lu-le-lo-s-Nintendo-64-Collection One day, it'll probably be worth schmillions of dollars, if current trends continue.
I have 2 at the moment, and I only got my second one because it was the Pikachu version for $10. After finding the controller at the same shop a week later for $2, it's easily worth about $100, if I sold it.
I have a few N64's as it was cheaper to buy them with Controllers, than it is to buy original controllers separately, also taking postage into account. Going back to the original question I guess you could always just plug them in when you need to use them, rather than having them all plugged in at once? Also then means they can be stored away when not in use allowing more space for other things.