Honestly, Z77 + i7-3770 isn't really that much of an upgrade, and having a few Ivy Bridge Xeons around, I'm kind of "a fan" of Ivy, if you can call it that. One exception would be power consumption, where Ivy is an Intel champ. I love dabbling with old systems, but I also don't know if I would recommend it. I'm in the US, and I keep an eye on ebay for i7-3770 and 3770K just for the heck of it, but I'm not impressed by the value. If you did go ivy, you would gain PCIe 3.0, DDR3-1600 officially, and maybe some slight USB and SATA advantages.
I think looking at a Ryzen 5 type new system makes a lot of sense from an overall perspective. IMO. I love high clock speeds and single-threaded dominance, I really do, but over the course of 2017 I settled on two Ryzen 5 1600 PCs for my home: One Windows 10 and one ESXi/vSphere. Whether Intel or AMD, some of the upgrade benefits are due to higher clock speeds (like Kaby and Coffee Lakes) and platform advantages like DDR4 and NVMe. You won't find those benefits in a Sandy or Ivy or Haswell upgrade.
One reason I say it may not feel like much of an upgrade - I inherited an i7-920 system on a nice Asus Rampage Ii Extreme mobo last winter. It's just a garage, play-around system. I didn't remember much about such an old platform, so I had to refresh my memory on FSB and how to overclock with it. But reading that my stepping of 920 was an OC champ, I slapped an H100i V2 on it, and cranked it up to 3.8 GHz. Ten years old, and that CPU is still a bit of a champ in its own right. Sandy Bridge gets a lot of accolades, but the OC 920 system is a fine desktop PC, except for power consumption (which is absolutely ridiculous, but hey, hydropower around my parts). I've got Sandy Bridge and Ivy Bridge E3 Xeons that have clock speeds in the neighborhood of that 920, and while not exactly a great comparison (not many of the Supermicro mobos they're in can handle a GPU), I don't feel much difference with identical RAM and SSDs between them all.
Be careful on inserting this (or any G34 chip) into the socket. Once you pull that restraining lever, it is either a good install or a piece of silicon jewelry.