Does it make economic sense to brew your own? You may be surprised to hear that the answer is yes. Once you have purchased an entry-level brewing kit, you will need to buy bottles (unless you have been saving empties), and a malt extract kit, and then you can get started.
While malt extract kits are not that expensive, beware of the tempting upgrades. Start with just the basics so that you get a feel for the process, and then decide if you want to continue. If you do, it will probably be worth your while to purchase some of the upgrades and accessories. Even while adding to your kit, you can keep costs down by using less-expensive items such as food grade plastic buckets and sterile surgical tubing. Remember to keep sanitation as a top priority when making lower-cost substitutions.