5 DASH is still a fair price for proposal submission. It should not be changed, IMO, at current DASH prices. (From my point of view, when the DASH price exceeds ±20USD, then it might start to become "expensive".
As I see it, if one does not have enough belief in his own proposal (enough belief as to justify the 5 DASH fee payment) this means the proposal is not "relevant" (this person should abstain from submitting such proposal, first of all).
Also, my opinion is that all the fees paid for proposal submissions should be 100% directed for the DASH Foundation budget, instead of burned... but I understand that this may be a controversial idea, anyway.
Yes, I want a lot of small proposals with more diverse creative talent. We won't get that with a large fee to submit them. Maybe a lot of the masternodes decide not to vote on the small proposals. Only need 10% yes to pass so it doesn't require 100% participation. It also allows the option for certain votes without significant expense.
If you have micro-proposals owned by a project manager, you are stuck having a well known core person wasting time managing, providing updates, etc. Decentralize it, save time, and let the process do the work.
As for spam, it isn't a 30 second process to submit a proposal. It takes time and requires some reading, at this point just the difficulty in submitting a proposal is probably enough to discourage spam.
The problem is the system being flooded with tiny
unimportant "not so relevant" proposals, with people "left, right and centre"
spamming proposals that, instead of contributing to the improvement of the system, will only create a mess and a decrease in decision quality....
... not everything has to necessarily pass through the voting system: there are many "tiny" decisions that are not "worthwhile" enough to justify moving the system, and so risking confusing/dispersing the attention of the community/voters.