If you have basic soldering skills its not too difficult. I bought my board on the Neo-Geo forums, the community is more based around passing the stuff along and you'll find much better deals there than on eBay.Also, how hard is it to consolize a board?
Mine consisted of a $20 arcade power supply, a $15 Jamma harness, $4 15-pin D-Sub connectors, and a $60 neobitz-s video encoder. I had project enclosures laying around, but none were big enough for the power supply and I couldn't find a larger one locally. You can try to find one, or build your own. It probably won't cost you more than $20 either way.
Now, you can build your own video encoder (neobitz sells kits, I was just in a hurry to get this done so I picked up pre-assembled). There are also a few articles around about harvesting one from original model Playstations. This will save you a couple bucks. If you have a lot of wiring and patience, you can also wire up your own Jamma harness, which can save you a few dollars.
You can also use a PC power supply to save a couple bucks, but the arcade ones require a lot less fussing for a minimal investment.
That being said, $200 for a pre-made one is a great price. If you want to do the project yourself, have parts laying around, or are capable of cutting some of costs then by all means do it. Let me know and i'd be more than happy to help you out.
To be fair - with the USB sticks, it's really easy to add multiple players. You can get a 360/PS3 stick running on there in a matter of minutes, and with most computers having HDMI (or if the TV has VGA) outputs, you can have a fairly decent experience with it.Also, MAME is a typically 1p experience where most of the Neo games are a 2p experience.
To each their own. I don't think either way is a terrible option.

