You can't even get an amd fx 8xxx + mobo + ram for the price of an i5 much less zen. Amd isn't in the market of making budget items, they've had to lower their price to compete on a dollars/performance ratio with intel. They'd have pretty lousy luck trying to sell an fx 4xxx for the same price as an i5 simply because they both have 4 cores. If a quad core zen competes with a quad core i5 or i7, expect pricing to be similar. Amd could use the cash so they're not going to be handing out bogo's or coupons on day 1.
Of course you can wait for zen, nothing against it. Just have realistic expectations. All things considered it's not generally a good upgrade if it means buying into a whole new platform, ddr4 ram, new mobo, new cpu, a reinstall of windows. That's half a new build right there. The reason for people jumping ship from amd's fx cpu's, there was nowhere left to go. Very little improvement from an 8320-8350-8370 etc. Since you currently own a pentium, there's plenty of room for upgrades, an i3, i5, i7. Had there been something comparable like an amd 'i7' for am3+ then the suggestion would have been to go that route for those folks. As it turns out there wasn't.
Simply upgrading to a better cpu on the current platform would be a cost effecting and hassle free approach while getting the most bang for the buck since you can keep all your existing components.
I'm not sure why everyone thinks amd is super cheap and will force intel to lower prices, that's not really how business works. Look at it this way, if you're amd and you're backed up on your bills, do you want to sell your product for $1 over cost to force the competition to lower their prices? Or would you be happy (provided your product competed 1:1) to price similarly to the competition and make $10 over cost?
Back in the day before the core series cpu's and bulldozers and piledrivers, amd had a cpu that performed ahead of intel. As such, they sold it for more money, amd was more expensive. It's possible that many folks either forgot or weren't around in those days and only remember an amd with low priced products. That wasn't really by choice but rather necessity. Everyone and their brother has a mechanical gaming keyboard out there yet they still sell for around $80-100+. If it were true that competition would enter a market and undercut everyone forcing prices lower, where are all the $35 mechanical gaming keyboards?