What do you mean, making a comeback? It never went away! LOL! Every kitchen should have at least one well-seasoned cast iron skillet!
If you're looking to buy new, forget about Griswold and Wagner. Griswold actually stopped manufacturing in 1957. Wagner bought the imprint, but the product they sold as "Griswold" was nowhere near the quality that Griswold itself made. Wagner itself ceased production in 1998. The imprint was also purchased by another company, but the "Wagner" ironware being sold today is a far inferior product. Always stay away from those "bargain" skillets you see in the Family Dollar. If it's selling for $3.00 it's probably worth about $3.00. Your best bet for new ironware is Lodge. They have a wide variety of skillets and other ironware, and their catalog is available online. You can usually find them in the housewares section of major retailers, but I've found that if they don't have ironware in the housewares aisle, you can always find it in with the sporting goods (go figure).
The cost of a new cast iron skillet will be offset many times over with the years and years of service it returns, but if you don't want to pay full-price for a new skillet, then by all means hit the garage sales! This is where you'll find your Griswold and Wagner iron! Look for cookware that has been well-cared for, unless you're into restoring it. You can find real steals on iron at garage sales and flea-markets, plus the added benefit of a used pan already being well-seasoned.
Once you have your iron skillet, you'll wonder how you ever got along without it.