I bought one at JoAnns this summer, and am loving it. Especially the fact that it folds down on both sides until I'm ready to use it. I got mine for only $59 - so I'm feeling pretty lucky! I know in my area (Southern California) they go on sale at least a couple times a year...or there's always that lovely coupon.
As for the home-made ironing tables or tops, I haven't built mine yet, but a friend had a good suggestion...she stapled multiple layers of fabric on the top, and when one gets scorched or dirty, she simply cuts off the top one, and presto, a whole new surface. (She washes the old one, and uses the good parts to cut up for piecing.) She's been using hers for 10+ years and said she's not to the bottom of the stack yet, but soon will be. Then she'll just repeat the process.