Look at the Mill's Pride line of cabinetry. This is a relatively easy to assemble semi-custom cabinet line. They keep the costs down by being self-assembled on site and using a limited range of woods and finishes. Sold mostly through Home Depot I do believe, you can take a look at these in person there. HD also keeps stacks of the manufacturer's supplied planning grids to plan your kitchen layout and estimate your costs...
http://www.millspride.com/We recently opened up a mud room and pantry in our house and wound up more than *doubling* our kitchen's square footage to about 240 sq. ft. of space that will recieve new cabinets. We're still trying to decide what cabinets and floor finishes we want, but replacing all our current cabinets with a reconfigured design (uppers and lowers) and adding about the same amount of cabinetry in the new space for storage (mostly lowers and a few uppers), a planning desk, new pantry, and coat/shoes storage will cost us just over $3200 for the maple Hartford. The Sherwood oak was about $400 less IIRC.
But as for your cheapest solution (if your cabinets aren't in rough condition), yeah painting/refacing and new hardware are going to be your cheapest option. If your cabinets are melamine/laminate, you'll need to buy a special paint that covers laminate or melamine surfaces but you can still customize the color just like any paint. Wood cabinets will need to be stripped (if painted) and sanded down, then primed before painting...
In all honesty, unless the kitchen isn't meeting your storage needs or the cabinets are in such rough shape that only replacing them will help, I see no reason to not go with just painting and new hardware. It's a bit of work, but you will save a good chunk of change and improve your kitchen's look... Adding a new laminate countertop could also be an extra expense that you can justify from the money you'd save by painting, should you decide the current countertops don't match the look you'd like to have...
Here a couple of links on refinishing a kitchen...
http://www.thisoldhouse.com/toh/knowhow/kitchen/article/0,16417,202424,00.html (a long article discussing the pros-cons to painting versus replacing)
http://doityourself.com/paint/paintkitchencabinets.htm (a simpler explaination with a list of materials you'll need...)
http://www.diynetwork.com/diy/hk_cabinets_counters/article/0,2037,DIY_13942_2276151,00.html (another shorter how-to article)
Best of luck, and I hope you enjoy your new kitchen when it's done!