This question comes up quite a bit, but the answer is simple...what are you trying to do?
You shouldn't be setting your marketing budget before all else. Marketing is going to cost what its going to cost, so it's important to look at what you need done and to do some cost-benefit analysis to figure out what is worth the splurge!
For example: for simplicity sake, let's say you set your marketing budget for the year at $1,000. You know that the design and scheduling systems you want to use are going to cost you $10 a month each and the email/SMS marketing system is $15 a month. Then you add in $350 for event swag and $450 for printing flyers and marketing materials (business cards, name badges, welcome packets, event signage, etc.). You're already over budget for the year, and I've only listed expenses for maintaining, not growing.
The best way to set a marketing budget is to list out all of your maintenance, swag and materials and marketing system expenses for the year. Once you've done that, figure out what you want to do that year to grow in your marketing. Do you want to do more videos, but would like to hire out for the editing? Is the building in need of new signage so it can be better seen from the street? Is it time to switch to a hard copy newsletter? Don't forget the cost os postage!
Add it all up and see if this is a number you could live with spending, if it isn't, start prioritizing your growth efforts.
Your marketing budget should be set AFTER you know what you want to do and how much it'll cost to accomplish, and edited from there!