Depending on your definition of 'inexpensive', Dan Miller's microplates set comes with 5/8 lb plates.
Get the Dan Miller plates.
I have both. Problem with the washers is they are slightly less than 5/8 lb, so going 1.25, 2.5, and 3.75 is fine, except that 3.75 is actually a bit less than that, and when you jump to the next 5lb increment it's a bigger jump.
Dan's plates will even up the increments and also give you more options.
I'm not a big fan of microloading, and yes I do have micro plates. I find my strength can vary quite a bit from day to day and just go with how I feel. If the bar is too light I'll do an extra rep or two, or if the bar is too heavy I'll go to failure. If I'm feeling really strong I'll put an extra 5 - 10 pounds on.
I have dan millers plates and they're great. You can also get baseball bat weights.