I have mentioned ad nauseam that I am a big fan of +Smartsheet and use it to track all of my daily tasks and projects. I have discovered the power of adding a budget column to my tasks sheet. Stuff that relates to me, personally, has one big sheet that gets subdivided into sections and subsections for every aspect of being Shaine Lee Mata. Currently, it's a list with over 900 items. I agree with you that I have way too many items listed.
I imagine that one could either give up on ever getting around to 900 items, or truly put everything into making a dent in the list. Yet, it seems that I am perpetually removing items that are done and adding some back. There are items that never seem to come off the list. They do eventually, but it seems like they never do.
I wondered why some items were lingering more than others. Obviously, it's because I never got around to doing them; but, what was holding me back. So, I went down the list and asked myself what was stopping me from doing each one. Too often, for those particularly recalcitrant to-do items, it turns out that it was lack of money. Often, these items have a cost that I am, have been unwilling to incur at the time.
For example, if I need haircuts for my son and for me, I know it will cost me about $30. But, if I'm a bit tight on cash this week, I would schedule the shearing for the following week after pay day. Or, if I need to buy new tires, upgrades for the computer, a tool, or whatever. It makes sense to cluster these things around when I have money, and when I see the cluster is too big, move it to the next payday.
As it turns out, having a budget cell next to my to-do item helps relieve some of that "guilt" about not getting around to doing it. In fact, I will know I have a damned good reason for not doing it. I can see at a glance that the new SSD for my computer costs $125, and is not as essential as, let's say, $30 in groceries. When I have $125 to spare, then it enters my realm of possibilities. If you have a big spend coming up, it doesn't make sense to put other big spends on the calendar around that time.
But, the budget field doesn't only apply to financial costs. There are also time costs. There are some tasks that do not cost you any cash, in some measurable way. However, those tasks may cost you time, which is also a limited supply. If I know that something will take me 2 hours to do, I may hesitate to schedule it during busy days unless absolutely necessary.
Doing three 15-minute tasks is more feasible than doing one 2 or 3 hour task. Or, let's say that I'm feeling particularly smurfy and decide to take on those 2 hour tasks in the evenings after work. This means that I would only schedule the one item for that evening rather than try to fill every nook and cranny of my evening.
When it comes down to it, adding a budget to your tasks, whether a financial or temporal budget, forces you to make your choices based on priorities. Your priorities may change from day to day, or week to week; but, the budget gives you an objective measure for choosing to do or not do something. And with that, you can rest peacefully with the knowledge that those items remaining on the list are better for you than trying to kick them out ASAP while making you broke or time-starved.