Yeah, well, that's all Mults, not just buffered.
The best value is probably the Intellijel Buff Mult 1U. But, like it says, you need a 1U row for that.
The Doepfer buffered mults are rather cheap, but occupy 4HP. Erica Synths have a Pico 3HP one. Personally, I think in 3U land, a buffered mult really shouldn't be more than 2HP wide. So the cheapest option there is DIY. If that's for you, check out a DIY store in your country and build yourself one. That's the best value. Other than that, maybe go with Malekko or Intellijel.