It's not just the cost to the person who is renting out their points that needs to be considered, but also the cost of renting an alternative room. One of the main benefits of buying into
DVC is that Disney's rack room rates go up quite a bit each year - I'm not sure about the discounted rates. So, I would think that when a person is trying to decide whether to rent points or go through Disney then the increase to the room rates would probably need to be considered as well.
For example, If one year I can rent points from a member for a room that would cost $2000, but I only pay $1200, I might decide that its a great deal.
Now, if the next year the rate that Disney is charging goes up 10%, that same room would cost $2200. However, if the cost to rent the points went up %10, it would cost $1320. I would actually be saving $880, instead of $800. In other words, I would still be saving 40% by renting the points from a member, but it would be more money that I've saved. (NOTE: I just picked numbers out of the air here. The 40% and 10% are just an example to illustrate the point.)
A completely different way to look at this is this: I joined DVC to pre-pay my vacations. If for some reason I can't use my DVC vacation for a year that doesn't mean that I don't want to be able to take a vacation, but that I may have to do it some other way. So, my vacation may now cost me more because I can't use my points to pay for it. Now maybe that should just be my loss, but I'm sure not everybody looks at it that way.
I just think that there are definitely at least two sides to this situation that need to be considered and that the value of the points will be determined by the two parties involved. I don't think that we need a concerted effort to raise the point rental price. Nor do I think that we need to try to keep them low. The only concern that I have with renting is those people who seem to be in the business of renting out points consistently. However, given the current state of things, I don't think that there is much that we can do about it.