It's pricy....but lets do a value calculation.
If I run one 5e campaign of about 1 year in length, playing each week for 52 weeks, for 4 hours each session...that's 208 hours. Divide $150 (assuming the Three Core Books model) by that to get $/hr, and with a little rounding for neatness, we've got $0.75 per hour.
Is 5eD&D worth $0.75/hr to me and four of my friends (which, if I got them to help me buy the books, we'd have about $0.15/hr/person)? Yeah, I think so. I spend significantly more when I hit the pubs for a night.
At $40/book ($120) would be ~$0.60/hr, which means we're looking at a fifteen-cent-per-hour increase in the cost to play D&D form 2008. That's not too bad for me. It's a big jump, but I can eat it. If I was a bit more on the fence about 5eD&D, maybe I didn't anticipate playing more than 1 session of it to "give it a try," I'd imagine I'd go for the starter set at $40, and then we'd be looking at about $10/hr, or $2/hr/person, which isn't the worst value in the world (maybe about in line with a night's drinking at that point, but like sharing your drink with four other people at the same time!).
Is one session of 5e D&D worth not going to the pubs one night? Yeah, I think I can sell that to myself.
There's also no telling what digital initiatives are coming down the pipe, or if they might try OGL again, or they sell it on PDF, or what other ways there might be of getting that content. I'd love to see something like the Compendium continue into 5e, at least. But that's all big speculation.
It's a jump, and it's not insignificant, but I think it's still a value for me. D&D continues to be a pretty affordable hobby, all things considered. A little less so, I guess, if you don't actually play that often.