FWIW we've been quite happy with a two-step "waiter's" corkscrew that we picked up at Trader Joe's for a few dollars. Our son recommended it to us - he's since moved on to a Rabbit but this one gets the job done for us quite nicely. A search will show these for sale from $8-15.
We added a foil cutter to our inventory as well. It works much better for us than the little knife found on many corkscrews.
Cheers,
Fredd