I can 100% confirm the "big brands" still sponsor club players - I've got a multitude of applications from players previously sponsored by Adidas, Gray Nics and Kookaburra (amongst others but those are the main culprits).
These do tend to be players involved with District/Minor County set ups as a minimum, but it varies massively and I've seen average players receiving heavy discounts from the bigger brands. You've got to remember with the big brands they sell the major of their kit at trade price to retailers, not directly to consumers, so the RRPs you see are largely irrelevant as they rarely ever sell kit at this price - if they can sell direct to players as part of a sponsorship arrangement, but at roughly the same price they sell to retailers, then they're no worse off (except having to faff with selling direct and pi**ing retailers off I would've thought!).
It's no secret that some brands' whole business model revolves around these discounted sponsorship deals. I would happily go into more detail but don't want to be at risk of libel lol.