i am into that kind of thing :-) if i wanted to try this kind of stuff at home, i.e. buying any necessary hardware myself, how much do you reckon the whole setup would cost? any suggestions on used NICs/switches to try this with?
You can get experience with ordinary Intel hardware and AF_XDP or DPDK.
Might also want to look at Packet. They offer bare metal cloud servers by the hour, some of which have Mellanox NICs in them[0]. I'm less familiar with Mellanox than SolarFlare, but I think they have a similar feature set.
My employer's customers don't use Mellanox anymore, so I haven't. I don't know why they don't, but would not be surprised if price had something to do with it.