VLB cards aren't expensive, they are just not common. Anything from ATI, Cirrus, S3/Diamond, and Tseng tend to be decent cards, although S3 tends to be on the higher end of that spectrum.
I managed to pick up a very nice Diamond Stealth SE VLB with a Trio32 chip on it. It's not the fastest VLB cards, Trio64 cards can be much greater, but for the 40 bucks I paid, it performs BRILLIANTLY.
You also will want to upgrade the memory in most cards. It's piss easy and dirt cheap (Piss and dirt, eh?) some cards use DIN style memory, while some use JLead, it's just a matter of figuring out what type of memory, what speed, and what package. Mine was: http://www.ebay.com/itm/172225519657 shipped from Israel (Not fast, took longer than the motherboard from Russia) and as you can see it's a few bucks for an, in my opinion, REQUIRED upgrade. Now I can go up to 1280x1024 resolution (256 colours only and only on a monitor that supports the strange video mode it uses) and 32 bit full colour is available at 640x480 allowing for dazzling graphics on newer 2D titles.
One thing to note, if you buy a VLB system, it will never do 3D to my knowledge. Even though VLB (Using the right CPU) is faster than PCI, there was never a card made to take advantage of it for 3D because it died within a year.
And if you want an I/O card, get something from DTC. They are great boards, but if you REALLY want to do pro, get a SCSI controller and use converters for either modern IDE or SATA drives (Or even use an Ultra320 drive, they are being pawned off for pennies). My M/I/O card was this: http://www.ebay.com/itm/252600035007 which he is still selling here: http://www.ebay.com/itm/Data-Technology-Corp- … D-/252679447019?
Happy 486ing!