Understanding what am I talking about:

The MVS (Multi Video System), as the Neo Geo was known to the coin-operated arcade game industry, offered arcade operators the ability to put up to six different arcade titles into a single cabinet, a key economic consideration for operators with limited floorspace. With its games stored on self-contained cartridges, a game-cabinet could be exchanged for a different game-title by swapping the game's ROM-cartridge and cabinet artwork. Several popular franchise-series, including Fatal Fury, The King of Fighters, Metal Slug and Samurai Shodown, were released for the platform.

The Neo Geo system was also marketed as a very costly home console, commonly referred to today as the AES (Advanced Entertainment System). The Neo Geo was marketed as 24-bit, though it was technically a parallel processing 16-bit system with an 8-bit Zilog Z80 as coprocessor. The coprocessor was used as a CPU, and for sound processing. The Super Nintendo and Sega Genesis also had similar co-processors, but neither Sega nor Nintendo claimed they were 24-bit.

The Neo Geo was ranked 19th out of the 25 best video game consoles of all time by the video game website IGN in 2009. In 2012, Blaze Europe announced the release of the Neo Geo X, an officially licensed handheld version of the original Neo Geo console with 20 games pre-installed.

Source: Wikipedia

So why not buy a AES system, that is already consolized and ready for home use???? 

Because, even though the system itself is not the most expensive thing (running around $200-$300),  the games are,  and the MVS's version are cheaper. At this point, my trade off is a little bit more money and a lot of work to build the console, for cheaper games; not really more money, but definitely more work, to build the console out of the arcade board.

Let me give you some price's example:

	MVS	AES
Metal Slug 3	$30	$300
King of Fighters 98	$30	$100
King of Fighters 2001	$65	$87
Fatal Fury	$80	$240
Samurai Shodown 2	$40	$30
Windjammers	$50	$130
Pulstar	$50	$500

Source: RacketBoy