I would agree that mid range clubs would be around $700. Starter sets, which are full sets of clubs and a bag, can cost under $200. While they are not great quality, they might be helpful if you're trying to get started on a budget. Buying used clubs can also be a good strategy for putting together a decent set without breaking the bank. I know you don't want second hand, but you can get really good stuff for cheap if you go that route.
A membership is only needed if you're planning to join a club, and that would be an unlikely move for someone who is interested in learning the game. The cost of memberships vary greatly. In some parts of the USA you can join a club for around $1000, and in others that wouldn't even cover 5% of the initiation fee much less the dues and fees. However, the latter clubs aren't usually the kind you join, they're the kind you're INVITED to join. You won't want to join a club until you're sure you enjoy golf. You're much better off cutting your teeth on public courses which tend to be less difficult, and are often full of less experienced players.
Playing at public courses is not that expensive. For one, a beginner will have a much better time if they play in the afternoon when the course is less crowded. Mornings tend to be more crowded and the regulars, the more experienced players, are out and they expect to get around the course in a fairly good pace. They're often not too patient with beginners. The good news is that most courses offer twilight, afternoon, rates that are often around 30-40% less than the morning rate. Public golf rates vary greatly by region as well. In rural areas you can play for under $20 if you walk the course. Many municipalities own and operate courses and offer great discounts to residents. I live in NJ which isn't the cheapest place to play golf and my local muni course is only $35 to walk in prime time if you're a resident. I would be surprised if you weren't able to find a round for under $50 regardless of where you live, and you might be able to play for much less than that.
The dress code at almost any public course is, at most, collared shirt and no jeans. If you own a shirt with a collar and a pair of khaki pants or shorts then you're home free. You'll only need to get a pair of golf shoes, and that can be done for under $50.
A beginner is usually better off playing the cheap distance balls since they tend to fly a bit straighter than the more expensive balls, and those are inexpensive, often around $10 a dozen. A decent mid range golf glove is around $10-12. Tees are dirt cheap, and that's about it.
Golf is not a rich man's sport.Once you have a bag of clubs and the basic supplies you can play a lot and spend less in a year than a pack a day smoker spends on cigs.