Cheap=Not good! You get what you pay for bro!
I like Advanced Nutrients sensi line of nutes for hydro, not cheap, but works well.
I would say he's right on this. You can look at it two ways; one way says a newbie should use cheap stuff so if they mess up it doesn't cost as much, the other way says not to use cheap stuff since it often requires a more experienced hand to overcome the corner-cutting it takes to make those products cheaply.
Some guys grow decently on MG. But it's definitely harder to get good results that way than with Advanced Nutrients. The extra work isn't worth it to me to save a few bucks up front (and I've never seen really top-notch results from MG anyway.)
I subscribe to the latter theory. If you want to learn to drive, use a nice reliable car. Save the jalopy for when you've mastered the art of NOT plowing over mailboxes.
I think there is a TON of hype and mass hysteria with nutes & soil. Learn to read your plants (and basic gardening) and you can do it all on the cheap. Hydro is a bit more finicky.
This is a good point. If you're growing in soil there's definitely benefits to be had from using a high quality fertilizer, but it's less important than when you're growing with hydroponics. Soil is much more forgiving of little mistakes and lower quality.
I still recommend not cheaping out on nutrients whether you're going to use soil or hydro (I mean let's be honest, you want a great harvest whether it's your first time or fiftieth, right?) but if you're using soil... well you can get away with it if saving some money is important.
Indoor growing just isn't a cheap hobby. It's not as expensive as some, but it still costs a bit to do well.