I just recently began setting up an inexpensive (cheap) workspace. Here are a couple of items and comments.
I'm fussy about desk height particularly with regard to typing/mousing comfort. I wanted a desk having an adjustable height.
At IKEA, I found this tabletop. It's large, has a nice writing surface, and has a rounded edge which adds greatly to working comfort. It was the largest, cheapest top they had. It is pressboard, not solid wood. For me, it has a pleasing if a bit "workroom" appearance. Note that, being pressboard, it will not support heavy loads. I simply cannot e.g. sit on it, stand on it, etc. It also might have difficulty with a monster CRT. Check the specified weight limit.
Table top: VIKA PERSBO
http://www.ikea.com/us/en/catalog/products/50071207
For legs, I got lucky. The following trestle legs, normally $30 each (I seem to remember $20, but the former's what the website says, now) were on sale for $10. Note that they have adjustable height, and that the front and back heights can be adjusted independently to place the surface on a slant, similar to a draftsman's table (though more primitive).
The height is adjustable; however, I found that the minimum height is still too high for my typing comfort (I like a lower surface). But, since the trestle is wood, it's quite easy to simple remove an inch or two from the bottom of the legs. If someone else subsequently wants to use the unit at a more standard height, they can simply adjust the surface upwards.
Legs: VIKA ARTUR
http://www.ikea.com/us/en/catalog/products/20070662
To attach the top to the trestle legs, the trick I learned from an IKEA employee is to use adhesive backed Velcro strips. That is how they construct all their in-store set ups, and it is much more stable than the little "peg fits into hole" method built into the construction and provided hardware.
For example:
http://www.velcro.com/index.php?page=industrial-strength
Product 90593:
http://www.velcro.com/products.php?sortBy=category&catId...
Refining their approach, mine was to figure out the position the legs would occupy under the top. Figure out where the Velcro strips on the trestle top will be; I left the screw heads visible for possible future disassembly. Make them long enough to allow for some adjustment, e.g. 4 - 5 inches each.
Locate where the center of those strips will meet the underside of the top. Apply the complementary Velcro material in strips running perpendicular to this; again, make the strips long enough for some ad hoc adjustment.
Position the trestles. Match the top up with one trestle -- it helps to have two people for this. Then adjust the other trestle as you lower the other side.
The Velcro holds things together quite well.
As an alternative to the trestle legs, IKEA offers a variety of metal legs that screw into the bottom of the tabletop -- the top is even predrilled in a pattern that accommodates many of them. The cheapest of those legs are simple metal tubes, at a fairly standard height, for $5 apiece. It appears they would make an ok table, although not as stable as the trestle legs (which make a quite stable unit). They can be lowered with a hack saw, if needed. IKEA also has adjustable, individual metal post legs, but they feel too wobbly to me. They have higher end leg pairs, including adjustable ones, that may be more stable, but I was doing this on the (extreme) cheap.
So, to wrap up this overlong description, I have two of the Persbo tops, with trestles, that I will use in an "L" shaped configuration. The each top is large enough to easily accommodate a multi-monitor set up -- again, though, check weight. Maybe buy and set up one unit, first, to make sure you are happy with the results. If not, you still have a good, cheap work table -- maybe drop the printer and other stuff on it.
I feel I went way over the top in my description, but I've been pleased with the results so far, felt it was a good "hack" of my workspace, and enjoy sharing knowledge I've won, of whatever sort. If you do give it a go and it works out for you, let me know.
Oh, finally, re IKEA, prices, and "disposable" furniture. IKEA advertises that many of their wood products are from sustainable lumber. But I just saw an article recently that says this isn't necessarily true. They have only something like 8 inspectors checking lumber sources, and this just doesn't cut it. Probably, they are still ending up with a lot of black and gray market lumber, including apparently stuff coming out of Eastern Russia. So... If you buy / use their stuff, treat it like other, more expensive furniture: Maintain it, and if/when you get rid of it, pass it on for further use and do not simply junk it.