Slush fund Logrolling

In my house which I have discussed before, we pay a fixed rate for rent and utilities each month. Since utilities vary month to month, we often have excess money to spend on house needs – we call this the "slush fund". Most things that a member of the house wants to use slush funds for must pass a simple majority vote. There are also two main games in the house – Super Smash Bros™and Ping Pong. I don't play much Super Smash Bros, as I prefer to play ping pong in my free time.  A little while ago, the Smash Bros. enjoiers lost one of their controllers.  Around the same time, the net to our pingpong table broke. The Smash Bros faction proposed that we use the slush fund to buy a new controller. They knew however that this vote wouldn't pass with just their faction. One of them approached me and said that he would vote to use the slush fund to buy a new ping pong net if I voted for the controller. 

In making this offer, my housemate shows a great example of logrolling as Muller discusses in chapter 5.9. My friend wanted to exchange votes so that both issues would pass. He would not gain much benefit from the ping pong net, and I would gain nothing from the new controller, but now we would both have motivation to vote for both issues. Since the cost of each would be split among the 17 people who live in the house, our marginal benefits would outweigh our private marginal costs of getting both. This would help us both, but it would present an issue to the house. It very well may be the case that the social marginal benefit for these two is lower than the social marginal cost. This would mean that while my friend who plays Smash Bros and I would both be better off, the house would be spending more than is allocatively efficient. Luckily the controller was found, and the pingpong net was fixed with duck tape, and the crisis of misallocating slush was averted.