This set of contracts would allow a whale to easily buy many more tokens per block in the case of a sale w/ limited amount by addr, and a limited number of contributions per block. Has not been tested/reviewed :)

TokenHolder.sol

pragma solidity ^0.4.10;
import "ERCToken.sol"; //Assumes ERC Tokens standard

contract HoldTokens {
    address owner = msg.sender;
    ERCToken token;
    
    function buyTokens(bytes data, address tokenAddress) payable {
        if (msg.sender != owner) throw;
        token = ERCToken(tokenAddress);
        if (!token.call.value(msg.value)(data)) { //this call buys the tokens
            throw;
        }
    }
    
    function transferTokens() {
        if (msg.sender != owner) throw;
        if (!token.transfer(owner, token.balanceOf(this))) {
            throw;
        }
        suicide(owner);
    }
}


contract TokenBuyer {
    HoldTokens[] tokenHolders;
    uint startingIndex;
    ERCToken token;
    
    function buyTokens(address tokenAddress, bytes data, uint maxAmtByAdd) payable {
        token = ERCToken(tokenAddress);
        while (msg.gas > 50000) { //should find real gas cost
            HoldTokens tokenHolder = new HoldTokens();
            tokenHolder.buyTokens.value(maxAmtByAdd)(data, tokenAddress);
            tokenHolders.push(tokenHolder);
        }
    }
    
    function transferTokens(address to) {
        for (uint i = startingIndex; i < tokenHolders.length; i++) {
            if (msg.gas > 50000) { //should find real gas cost
                tokenHolders[i].transferTokens();
            } else {
                break;
            }
        }
        startingIndex = i;
        token.transfer(to, token.balanceOf(this));
    }
}